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Open Compute Developing Wider Rack Standard

timothy posted more than 2 years ago | from the so-many-to-choose-from dept.

Facebook 237

1sockchuck writes "Are you ready for wider servers? The Open Compute Project today shared details on Open Rack, a new standard for hyperscale data centers, which will feature 21-inch server slots, rather than the traditional 19 inches. "We are ditching the 19-inch rack standard," said Facebook's Frank Frankovsky, who said the wider design offered better heat removal and a unified approach to power, including a 12 volt busbar. The Open Compute Project, developed by Facebook to advance open source hardware design, believes an open approach can avoid the mistakes of blade server chassis design."

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237 comments

Clouseau: The case is solv-ed (4, Informative)

alphatel (1450715) | more than 2 years ago | (#39878403)

So put the server power supply on the outside, basically.

Re:Clouseau: The case is solv-ed (1)

a90Tj2P7 (1533853) | more than 2 years ago | (#39878641)

So put the server power supply on the outside, basically.

That summarizes it more frankly than Frank Frankovsky did.

metric? (5, Insightful)

SkunkPussy (85271) | more than 2 years ago | (#39878411)

The first mistake is that they are still talking in inches instead of metric units.

Re:metric? (3, Insightful)

Anonymous Coward | more than 2 years ago | (#39878695)

Arguing metric vs. imperial units is pretty much the epitome of bikeshedding.
We can do arithmetic nowadays.

Re:metric? (4, Funny)

Christian Smith (3497) | more than 2 years ago | (#39878787)

Arguing metric vs. imperial units is pretty much the epitome of bikeshedding.
We can do arithmetic nowadays.

We can do, but people (even rocket scientists!) still get it wrong: http://en.wikipedia.org/wiki/Mars_Climate_Orbiter [wikipedia.org]

Technical issues should use SI units.

Re:metric? (5, Insightful)

Anonymous Coward | more than 2 years ago | (#39879013)

http://en.wikipedia.org/wiki/Mars_Climate_Orbiter [wikipedia.org] Technical issues should use SI units.

The Mars Climate Orbiter was a case of someone not labeling their units. The unit system wasn't the problem.
Secondly SI isn't always the best unit of measurement for performing calculations. In plasma physics we use eV in stead of joules for energy because it simplifies our work. In astro physics measuring distances in the SI unit of length, the meter, is impractical. If you are doing anything with relativistic electro magnetism, it's best to do your calculations in cgs because it eliminates useless constants.

Re:metric? (2, Informative)

ChatHuant (801522) | more than 2 years ago | (#39880053)

The Mars Climate Orbiter was a case of someone not labeling their units. The unit system wasn't the problem.

But units wouldn't need to be labeled if everybody used the same system. The continued existence of the zombie Imperial system is the root cause of the problem.

Secondly SI isn't always the best unit of measurement for performing calculations. In plasma physics we use eV in stead of joules for energy because it simplifies our work. In astro physics measuring distances in the SI unit of length, the meter, is impractical

Which is why SI has a number of accepted units [nist.gov] . You'll note that both the eV and the astronomical unit are there, but not the feet or yards used by Lockheed to send a rocket past Mars.

Re:metric? (5, Insightful)

Anonymous Coward | more than 2 years ago | (#39880303)

But units wouldn't need to be labeled if everybody used the same system. The continued existence of the zombie Imperial system is the root cause of the problem.

Which is why SI has a number of accepted units [nist.gov] . You'll note that both the eV and the astronomical unit are there, but not the feet or yards used by Lockheed to send a rocket past Mars.

ALWAYS LABEL UNITS! This was the ONLY cause of the problem with the mars orbiter. If Lockheed used kilometers as their units instead and Nasa assumed meters the probe still would have had problems. If I tell you I have an energy of 5 does that mean 5 eV or J? You don't know if I don't label it.

Re:metric? (2)

spire3661 (1038968) | more than 2 years ago | (#39880321)

Logically false. You are saying that the existence of a different measuring system is the cause of the human failure to differentiate. It was a human failure, what you are asking for is to dumb it down so humans cant fail in that way anymore. I assure you, humans will find some other way to foul it up, no matter how many rubber bumpers you put on things.

Re:metric? (1)

246o1 (914193) | more than 2 years ago | (#39880529)

And your argument in turn implies that there's no point in ever trying to be systematically consistent to reduce errors, because .... What? The frequency and severity of human error is going to be constant regardless of the systems people are forced to work within?

People will continue to make mistakes. In some cases, the existence of confusing doubles standards increases the chances of that happening, as well as introducing pointless costs. Measurement is a wonderful example of a natural monopoly, and we should prefer (open) standards.

Logically false. You are saying that the existence of a different measuring system is the cause of the human failure to differentiate. It was a human failure, what you are asking for is to dumb it down so humans cant fail in that way anymore. I assure you, humans will find some other way to foul it up, no matter how many rubber bumpers you put on things.

Re:metric? (2)

dj245 (732906) | more than 2 years ago | (#39880517)

But units wouldn't need to be labeled if everybody used the same system. The continued existence of the zombie Imperial system is the root cause of the problem.

No, you should always label your units. My company's (Japanese-based) engineering document system usually lists material stock dimensions in mm. Except for the times that it lists it in meters. And sometimes it is ambiguous where the decimal point should be since that isn't listed (and we often work in 100ths of a mm). There is plenty of confusion because some idiot Japanese designer didn't list his units, and imperial units aren't involved.

Re:metric? (1)

hobarrera (2008506) | more than 2 years ago | (#39878889)

While I share the same hatred towards imperial units that most non-US people feel, this doesn't deserve to be downvoted, it's quite true, and GP is just trolling IMO.

Re:metric? (3, Funny)

MetalliQaZ (539913) | more than 2 years ago | (#39879015)

Actually, I think deliberations over the color of a bike shed is the epitome of bikeshedding.

Re:metric? (0)

Anonymous Coward | more than 2 years ago | (#39880033)

<quote><p>Arguing metric vs. imperial units is pretty much the epitome of bikeshedding.
We can do arithmetic nowadays.</p></quote>

You have no idea how often this comes up in a particular industry (mine). We deal with critical temperatures in computer rooms (among many other things) and i have had this conversation way too often: "We see the values from your system come through in C, how do we get them in F? My software (of which I am fully in control of the programming therein) is expecting the temperature in F because that is what my user wants. Why don't you convert it to F on your end?" ... "Sir, the operation is val * 1.8 + 32 so if you simply use 1.8 as a multiplier (you have this feature in YOUR software already) and if you use 32 as an offset (you also have this feature already) you can easily show your user F instead of C." ... "Oh, well it would still be easier if you could reprogram your system to deliver the value in F."

Re:metric? (0)

Anonymous Coward | more than 2 years ago | (#39879135)

Why not use the existing 24" standard, probably because 21" is some metric (1/2 meter) number.

Re:metric? (1)

Frosty Piss (770223) | more than 2 years ago | (#39879405)

21 inches = 0.5334 meters, *not* 1/2 meter.

Not a big difference, but significant for mounting equipment...

Re:metric? (3, Insightful)

richardkelleher (1184251) | more than 2 years ago | (#39879449)

The first mistake is that they are still talking in inches instead of metric units.

This was my thought exactly. If we continue to build new standards around obsolete measurement systems we are just pandering to the Luddites. It is time to move America forward into the 19th century. If we can't engineer for the 21st century, we should turn the creation of standards over to people can.

Re:metric? (2)

jeffmeden (135043) | more than 2 years ago | (#39880343)

The first mistake is that they are still talking in inches instead of metric units.

This was my thought exactly. If we continue to build new standards around obsolete measurement systems we are just pandering to the Luddites. It is time to move America forward into the 19th century. If we can't engineer for the 21st century, we should turn the creation of standards over to people can.

Actually most server and rack manufacturers offer specs primarily in cm/mm, and include inches as subtext or a footnote. Upon closer inspection, the Opencompute stuff also offers all drawings this way in mm and in. I suspect they said "this will be 21 inches instead of 19" so it would be more generally consumable, since not everyone finds it as illustrative when they hear "this will be 538mm instead of 482mm". If you can't be bothered to look, then enjoy your time in the 18th century. The rest of us (even if we are in the US) are getting along just fine using the metric system.

Re:metric? (1)

spire3661 (1038968) | more than 2 years ago | (#39880371)

There is nothing obsolete about the Imperial system. Its a unit of measure like anything else. It may not be as elegant as some other systems, but it works just fine. DO you really need to be able to divide by 10 to feel better about it? The ONLY difference between metric and imperial is that metric is easily understood by idiots.

Re:metric? (5, Insightful)

David Chappell (671429) | more than 2 years ago | (#39880095)

The first mistake is that they are still talking in inches instead of metric units.

I would imagine that the reason is that 21 inch racks are already a standard. They are widely used in telephony. Introducing a third standard (say 55 cm racks) would likely complicate things for little gain. Better to just call them 5334 mm racks.

This has already been done repeatedly in engineering. When I visit Europe (I am an American) I see things in Imperial units all around me, but most of the time nobody but me knows that they are. 6 mm steel cable? Why not 5 mm? Because 6mm is 1/4 inch. While is their 900 grams of buckwheat in this bag rather than 1000 grams? Because it is a two pound bag filled eight grams short. Railway gage in the former Soviet Union? 1524 mm. Yup, thats five feet. See that 1220x2440 mm sheet of plywood. Yup, 4 by 8 feet.

This by the way is why it is so hard to convince Americans that they should switch the building and engineering trades to the metric system. All our building materials are sized on Imperial units. Converting these dimensions to oddball metric sizes would mean that builders would need to memorizes all sorts of weird dimensions and carry pocket calculators to figure out where the center of something is. There have been many serious attempts to do engineering projects in metric units. First they find out that they can't get materials in even metric dimensions. Then the vendors ask what they mean when they order 914.4 mm doors. Then the builders ask to have the drawings converted into 'the real measurements'. It begins to seem too much like masocism and on the next project they go back to units everybody understands.

Many professions and markets have converted to metric in the US. Medicine mostly has. So has alcohol distribution. So have laboratories. So have our automobiles. But, I don't see any way for the building trades to convert.

The metric system is clearly superior in scientific contexts. There the argument about ease of conversion is powerful. However this argument is meaningless in daily life. The only unit conversion the average person does is feet to inches. You don't need to know how many feet are in a mile in order to know whether you are exceeding the speed limit.

I have found one use for metric units in daily life: increasing ones 'geek cred'. Since expressing dimensions in metric units is a form of elitist obfuscation, it is a great way to be annoying.

Re:metric? (1)

jeffmeden (135043) | more than 2 years ago | (#39880441)

I have found one use for metric units in daily life: increasing ones 'geek cred'. Since expressing dimensions in metric units is a form of elitist obfuscation, it is a great way to be annoying.

Hah, too true. I love throwing out "do you mean short ton or long ton?" whenever someone uses the word "ton" as an expletive attributive in conversation. Did I mention that I am a vocabulary pedant too? Anyhow, don't forget about the true pinnacle of intellectual elitism, the completely useless and obscure systems of measurement (a good list is on wikipedia: http://en.wikipedia.org/wiki/List_of_unusual_units_of_measurement [wikipedia.org] ) Enjoy!

Wow. Awesome advances in technology! (0)

Anonymous Coward | more than 2 years ago | (#39878451)

They're changing the size of the hardware racks? HOLY SHIT, MAN. That's some crazy shit right there!

What's next? Changing the lightbulbs in the server room from fluorescent to LED?

So glad Slashdot is right on top of these great advancements in computing technology.

Re:Wow. Awesome advances in technology! (1)

xeno314 (661565) | more than 2 years ago | (#39878795)

Well see, we needed to boost revenues in rack hardware. With this, we can win either way! People buying new servers will need new racks, so $$$. People buying more racks who need to use some new and some normal equipment will have to buy adapters, so $$$.

I don't know whether this is really a net win on space vs. adding height to servers that need it in the current form factor, but hey, time to change things up, I suppose.

Re:Wow. Awesome advances in technology! (3, Insightful)

networkBoy (774728) | more than 2 years ago | (#39878811)

As soneone responsible for machine infrastructure, this is a big deal.
21" racks means that I have to change the layout of my lab. Currently we have the mandatory 42" aisle (or whatever ADA requires) running the length of the lab, with banks of racks pedistileing (sp?) out from the wall with power and data. If all the racks were 2" wider I'd lose a rack in each row, so unless these machines improve density... it's a no sell for me.

Re:Wow. Awesome advances in technology! (0)

Anonymous Coward | more than 2 years ago | (#39878837)

I hope you enjoy never upgrading your hardware.

Re:Wow. Awesome advances in technology! (4, Informative)

Doc Hopper (59070) | more than 2 years ago | (#39879579)

That's covered in the article. 21" racks within the current 24" standard rack size. By eliminating cable mass in favor of bus-bars, you gain the two inches "free" in your rack footprint. If the rack's designed right, you could even keep the same seismic bracing.

spinal tap hardware (2)

Hognoxious (631665) | more than 2 years ago | (#39878453)

These are better. They're 2 batter.

I don't see the point, to be honest. And aren't things supposed to get smaller as technology advances?

Re:spinal tap hardware (1)

lister king of smeg (2481612) | more than 2 years ago | (#39879535)

not necessarily, they will get built with higher computational density but the size will remain constant because the workload will increess enough to match moores law

2" shim market (5, Insightful)

RichMan (8097) | more than 2 years ago | (#39878457)

I detect a few years of market window for rails with 1" shims attached (19+2x 1" = 21) to allow old servers to wedge into the new racks.

Re:2" shim market (1)

istartedi (132515) | more than 2 years ago | (#39878825)

No way man. Spring-loaded adjustable shims. I'm off to the patent office. Just kidding; but I know somebody else probably IS off to the PO and isn't kidding.

Re:2" shim market (1)

David Chappell (671429) | more than 2 years ago | (#39880119)

No way man. Spring-loaded adjustable shims. I'm off to the patent office. Just kidding; but I know somebody else probably IS off to the PO and isn't kidding.

I don't see why they need to be adjustable. And you shouldn't be able to patent them because 21 inches is already as standard rack size. In fact, I think I have seen these shims somewhere.

Re:2" shim market (1)

David Chappell (671429) | more than 2 years ago | (#39880151)

Looks like I remembered incorrectly. Telecom racks are actually 23 inches wide.

Re:2" shim market (2)

MarkGriz (520778) | more than 2 years ago | (#39878851)

Or maybe Facebook becomes the new Myspace before this gains any traction, and we can avoid this altoghether.

Re:2" shim market (1)

gladish (982899) | more than 2 years ago | (#39879279)

So you're saying the business to be in is reselling chinese made server rack shims.

Re:2" shim market (1)

nschubach (922175) | more than 2 years ago | (#39879757)

The problem with 1" shims is that the copper power bars are still going to be in the way of the long server chassis. The pictures I saw had the copper bars running up the middle of the rack limiting your usable depth by quite a bit. (page 5 [opencompute.org] )

"awesome" (0)

Anonymous Coward | more than 2 years ago | (#39878479)

More and more standards. That's what everyone and the world always needs.

Not.

Re:"awesome" (1)

ArhcAngel (247594) | more than 2 years ago | (#39878677)

Obligatory XKCD [xkcd.com] reference.

Re:"awesome" (1)

Anonymous Coward | more than 2 years ago | (#39879249)

More importantly, breaking on of the VERY FEW damn standards that almost everyone seems to have complied too!

Seriously, in a world where no one can agree to use the same anything.. this was a small bastion of hope. The fuck is wrong with these guys!

Re:"awesome" (1)

PerfectionLost (1004287) | more than 2 years ago | (#39879427)

Everyone except the telcos.

Re:"awesome" (1)

ckaminski (82854) | more than 2 years ago | (#39880509)

Which was really "Just AT&T" until 1984.

Server width is changing Rack Width isn't (4, Informative)

darthcamaro (735685) | more than 2 years ago | (#39878513)

There is a big distinction that you need to understand here, the Width of the Server chassis is changing, not the width of the rack itself. The outer dimension of the Server Rack is staying at 24 inches. The REAL problem was a bogus amount of extra cruft in the rack design that is going to be eliminated to make way for the wider servers.

Re:Server width is changing Rack Width isn't (1)

afranke (1400099) | more than 2 years ago | (#39878709)

Yay, so that means that I can still use my lack rack. :)

Re:Server width is changing Rack Width isn't (1)

Anonymous Coward | more than 2 years ago | (#39879349)

Cruft like structural integrity to hold multiple 200 lb servers (i.e. Sun Thumpers)?

Re:Server width is changing Rack Width isn't (5, Informative)

IGnatius T Foobar (4328) | more than 2 years ago | (#39879415)

That "extra cruft in rack design" is where your cables go. I have an 18,000 sqft data center over here and I can tell you from experience that what you call "cruft" isn't nearly enough space for all of the cables once things start getting dense. We are actually considering 23" (telecom standard) racks with 19" rails in them for cabinets that aggregate the networking gear, just for this reason.

But oh no, far be it from Facebook to actually work with the industry. They screwed up the Internet and now they're going to screw up your data center.

Re:Server width is changing Rack Width isn't (1)

thereitis (2355426) | more than 2 years ago | (#39880039)

As technology advances, the time it takes to call a predecessor's design 'stupid' shrinks.

Re:Server width is changing Rack Width isn't (0)

Anonymous Coward | more than 2 years ago | (#39880101)

Facebook is in the data center industry. They already have more experience and larger centers than you have ever dealt with sweetheart.

already have 23" (2, Interesting)

Anonymous Coward | more than 2 years ago | (#39878525)

There's already a standard for 23" racks widely used in telecom. So now we have to deal with 19, 21, and 23 options? Great.

Why invent a new standard? (5, Insightful)

Anonymous Coward | more than 2 years ago | (#39878533)

Why invent yet another new standard when there's a perfectly good one already in use, with lots of inventory in place?

Telecom has used 23" racks for years. There are standard adapters already available to mount 19" hardware in a 23" rack. 23" racks are already available in the marketplace.

Further, why 12Vdc? Telecom has been using DC plant for decades and there is a ton of existing 48Vdc equipment on the market. There area existing cabling standards for all this as well.

Just seems like an attempt to fracture the market and create an opportunity to solve a problem that's already been solved.

Re:Why invent a new standard? (0)

OzPeter (195038) | more than 2 years ago | (#39878685)

Why invent yet another new standard when there's a perfectly good one already in use, with lots of inventory in place?

FB IPO .. FB IPO .. FB IPO .. what other reason do you need??!?!?!

Re:Why invent a new standard? (1)

Tekfactory (937086) | more than 2 years ago | (#39878733)

Doesn't Google use 12Vdc straight to their Motherboards, they have 12Vdc batteries for each server, and everything that needs 5Vdc gets power from the motherboard and not a power supply.

I would assume FB is trying to use the same equipment, I don't know if 48Vdc is as prominent on the server side.

Re:Why invent a new standard? (2)

Bill_the_Engineer (772575) | more than 2 years ago | (#39879235)

You need the higher voltage supply to make up for voltage drop due to resistance found in the power cable themselves. The longer the cable the larger the resistance and the more pronounced the voltage drop. You could compensate by increasing amperage (to make up for lost power) and using heavier gauge cables (to reduce the internal resistance and handle the increased amperage), but the accepted practice is to distribute a higher voltage to the equipment and use a DC-DC converter in the device or immediately at its power input to deliver the required voltage. This is because it's generally safer and cheaper (material costs, weight) to distribute higher voltage than higher current.

This is why telcos use 48Vdc and the aircraft industry (MIL-STD-704F) use 24 Vdc.

Re:Why invent a new standard? (1)

SuricouRaven (1897204) | more than 2 years ago | (#39879445)

This is in contrast with the standard ATX supply which runs, at a minimum, rails for 5V, 12V, 3.3V and -12V. The latter is really a leftover from powering old RS232 ports, but the standard still requires it. Even then the pins are so small that many pins in parallel are required, thus the sight of a ridiculous twenty-six-cable tangle winding it's way through your case like like a nest of intertwined worms.

Re:Why invent a new standard? (1)

RulerOf (975607) | more than 2 years ago | (#39880167)

the sight of a ridiculous twenty-six-cable tangle winding it's way through your case like like a nest of intertwined worms.

The mental image on that one is priceless :D

Thank you, sir!

Re:Why invent a new standard? (1)

ZeroSumHappiness (1710320) | more than 2 years ago | (#39880541)

If you search you can find a real image so you don't have to make a mental one. It's quite fascinating, actually.

Re:Why invent a new standard? (1)

hjf (703092) | more than 2 years ago | (#39878739)

Also, 12VDC? REALLY? so you have like what, 12KW (being VERY conservative) worth of gear in a 42U rack? that's 1000A right there! How the hell do you keep power loss low with 1000A?

Re:Why invent a new standard? (1)

afidel (530433) | more than 2 years ago | (#39879177)

Close, Each bus bar pair can support up to 500A, which can be increased by adding more copper. Each bus bar pair can support up to 6KW, while power can be increased by using more copper. The bus bars can be adjusted for higher current, depending on the desired power per column, as they are interchangeable. Normally the Open Rack has three bus bar pairs installed, but it is also configurable with two or one bus bar pairs in the power zone: link [opencompute.org]

Re:Why invent a new standard? (2)

tlhIngan (30335) | more than 2 years ago | (#39879699)

Close, Each bus bar pair can support up to 500A, which can be increased by adding more copper. Each bus bar pair can support up to 6KW, while power can be increased by using more copper. The bus bars can be adjusted for higher current, depending on the desired power per column, as they are interchangeable. Normally the Open Rack has three bus bar pairs installed, but it is also configurable with two or one bus bar pairs in the power zone: link

That bus bar had better be pretty damn big cross-sectionally. 500A is a LOT of current. And if there's three, that's 750A. You better put that power supply at the bottom of the rack, because the IIR losses are huge (they grow with the square of the current - pass twice as much current, and the loss goes up 4 times).

Pretty much the only way to have racks of it is to make the roof and floor out of solid metal and weld the racks to both sides (IIR losses are huge at connection points). Hell, that's how welding works - high currents, low voltage. Any bit of dirt between the rack's bus bars and the power cable will weld them together over time, if not cause a fire due to heat.

Hell, the voltage drops are pretty big as well. 500A, if the connection points add 0.01 ohms, you're looking at 5V. (And using IIR, that's a good 250W of power lost). Get it under 0.001 ohms and you're looking at 25W dissipation in the connectors and still half a volt of drop, which is nearly 5% voltage drop.

There's a reason why telecoms use 48V, and why electrical towers run at hundreds of kilovolts. It's the best mix of voltage conversions and acceptable power losses. Or why datacenters have other voltages like 208V or 240V readily available - lower the current and the cables can be made much smaller.

Heck, even *CARS* are considering switching to a 48V system to be able to power everything.

Re:Why invent a new standard? (1)

afidel (530433) | more than 2 years ago | (#39879931)

A power zone is no more than 1/3r'd of a rack (and can be as little as 1/9th of a rack but the spec still calls for the bus bars to cover the entire 1/3rd of the rack). Oh, and as far as 500A being a lot of current, sure but datacenters deal with large currents all the time, for instance the inputs to my UPS's are 300A at 480V and they're small by datacenter standards.

Re:Why invent a new standard? (1)

rev0lt (1950662) | more than 2 years ago | (#39880189)

Oh, and as far as 500A being a lot of current, sure but datacenters deal with large currents all the time

Usually not using DC, and not on a computer-tech acessible zone. Not only 500A can easily melt/vaporize metal (electric welders usually are on the 100A-200A range), but as the parent pointed out, the voltage drop is significant. And there is another motive why this is not very smart - ticker conductors are heavier and more expensive. Considering the increasing cost of copper, this will translate on an substantial increase in cost per rack.

Re:Why invent a new standard? (2)

afidel (530433) | more than 2 years ago | (#39880275)

And that increased capital cost will be completely and utterly dominated by the increased efficiency in power useage. If you think these guys haven't analyzed the numbers every which way and run a pilot datacenter to prove out their numbers before releasing this stuff you're delusional. These are not stupid people and they know exactly the problem they are trying to solve. It might not be the same problem as everyone else in the computer sector is trying to solve, but it is a problem quite a few very large web companies are trying to solve (ie this is a solution for Google, Microsoft, Facebook, Amazon, and a few other very large companies with hundreds of thousands to over a million servers).

Re:Why invent a new standard? (0)

Anonymous Coward | more than 2 years ago | (#39880479)

[...]Heck, even *CARS* are considering switching to a 48V system to be able to power everything.

42, actually, and that was the nominal charging voltage, for a 36-V battery. But that seems to be dead. http://en.wikipedia.org/wiki/42-volt_electrical_system

Re:Why invent a new standard? (1)

mpoulton (689851) | more than 2 years ago | (#39878743)

Mod this AC up! These problems have already been solved - decades ago. Sometimes it's better to look for solutions to your problem in another industry than to engineer it yourself. In fact, it's almost always better.

Re:Why invent a new standard? (0)

Anonymous Coward | more than 2 years ago | (#39878745)

12V DC is a great idea. Eliminate the power supplies inside each individual server and run the entire data center off one massive PSU.

It's ridiculous to take AC power, convert to DC to charge and run the UPS, then convert back to AC, only to have individual servers convert AC back to DC.

However, I think any new standards should also take a serious look at full blown water cooling solutions for main heat sources. Concentrate most of the heat into liquid and reduce the amount of air conditioning required. Easier to cool water than it is to cool air.

Re:Why invent a new standard? (1)

networkBoy (774728) | more than 2 years ago | (#39878867)

As others have stated, this is remarkably inefficient. There is a reason Edison lost the power distribution battle.
I think you may be able to run one PSU per rack, it's in the middle, with bus bars top to bottom, but beyond that you're looking at I^2*R losses that run over what you lose in the AC- DC - AC DC cycle of mains - UPS - PSU - MB
-nB

Re:Why invent a new standard? (1)

afidel (530433) | more than 2 years ago | (#39879205)

Actually they are doing three power zones per cabinet fed by 277V AC from utility and 48V DC for backup power which then powers the 12V bus bars.

Re:Why invent a new standard? (2, Informative)

Anonymous Coward | more than 2 years ago | (#39878891)

12V DC is a great idea. Eliminate the power supplies inside each individual server and run the entire data center off one massive PSU.

No, it's a stupid idea thought up by people who are ignorant in matters of distributing electricity. When you reduce voltage you increase amperage, there's no free lunch. Running bus bars around rated in the thousands of amps and up to distribute 12VDC is ridiculously stupid.

Re:Why invent a new standard? (3, Insightful)

rickb928 (945187) | more than 2 years ago | (#39879195)

It's not about the resistive losses, mate.

First, eliminating power supplies at each server eliminates multiple point heat sources. One honking rectifier stack somewhere does the job. Cool that separately, and maybe even more efficient conversions, though the jury is still out on that for me. Honking-er bus bars will not be as efficient as AC distribution, but the losses will be tolerable. Remember the stack? Getting that cooled outside the server room is useful.

Using 48VDC makes a lot of sense just because there is a pile of telco equipment made to do that, and well understood. It will have to be regulated at the server level anyways, and the current goes down also.

But then again, it's not about being compatible, nor even evolutionary. This is a revolution, and if the old guard can't be enslaved, it must be killed off. So telco standards are out of the question. Besides, those extra 2 inches.

Re:Why invent a new standard? (1)

Bill_the_Engineer (772575) | more than 2 years ago | (#39879847)

This is a revolution, and if the old guard can't be enslaved, it must be killed off.

Touching the 12Vdc @ 500A copper bar bus will kill off some of the new guard too.

Re:Why invent a new standard? (1)

afidel (530433) | more than 2 years ago | (#39879981)

These people aren't idiots, they've got very intelligent engineers and they are trying to solve a very specific problem which is how to minimize the cost per transaction for web scale platforms. When you've got a million servers (Google's been there for some time and Facebook is probably well on their way) a few percentage points in efficiency can be very real money, and if your design doesn't work for everyone that's ok because manufacturers will be happy to do a custom run of 50k units for your new small test datacenter.

Re:Why invent a new standard? (1)

nsaspook (20301) | more than 2 years ago | (#39879853)

Using 12VDC on any type of system that uses more than a few hundred watts is insane. Only a Best Buy boombox tech would think it was a good idea.

Re:Why invent a new standard? (3)

rev0lt (1950662) | more than 2 years ago | (#39880225)

Using 12VDC on any type of system that uses more than a few hundred watts is insane

Like in a car?

Re:Why invent a new standard? (1)

Anonymous Coward | more than 2 years ago | (#39879155)

If you think it's a great idea then fine, you go stick your hand in the rack with the 12v bus bar with 1000A running through it. That's the kind of excitement I'd rather not have, personally.

Re:Why invent a new standard? (0)

Anonymous Coward | more than 2 years ago | (#39879461)

It won't shock you unless you have studs piecing or open wounds that allows electricity to conduct more freely.

On the other hand if you drop a screw driver or any bare piece of metal that shorts it together, you'll have a major case of high current getting the metal to go red hot or even vaporize.

I wonder how the heck they are doing the power distribution inside the rack itself. i.e. what kind of insane size power connectors do they use? Car jumper cables to each server card isn't exactly usable.

Seriously guys. Last time I worked with -48 equipment 5 years ago, they had 97% efficiency unregulated PUPS (1/2 bricks) to down convert -48V to 12V. Just exactly what home made crappy converters did they used for their calculations for the 50% gain in efficiency?

Re:Why invent a new standard? (1)

avandesande (143899) | more than 2 years ago | (#39878799)

... the AC post should be nominated for one of the best ever

Re:Why invent a new standard? (1)

couchslug (175151) | more than 2 years ago | (#39878871)

Fracture markets for vendor-lock win!

Re:Why invent a new standard? (2)

Glendale2x (210533) | more than 2 years ago | (#39878945)

Because they called this one "open" and used a lot of green colors to imply its "greenness".

Re:Why invent a new standard? (0)

Anonymous Coward | more than 2 years ago | (#39879019)

Very good point on the 48Vdc. It's also the standard voltage in 802.3af Power-over-Ethernet systems. You can push the higher voltage at a lower current.

Re:Why invent a new standard? (1)

Anonymous Coward | more than 2 years ago | (#39879029)

Because this IS NOT changing the actual exterior rack width, it's deleting the 'dead space' older racks left for mounting brackets, side-routing cables, etc; most of which modern servers already eschew so it's just "dead air" space between racks that is outside of the airflow path so it's stale air.

Telecom racks are physically wider: 32" floor spacing rack-to-rack w/ 23" internal rail spacing. Data racks are 24" spacing w/ 19" internal rail spacing, this 'new standard' is purely to change data racks to 24" spacing w/ 21" internal rail spacing; in effect ditch some of the side-gaps entirely so servers can utilize the space for components.

Re:Why invent a new standard? (0)

Vairon (17314) | more than 2 years ago | (#39879293)

Computer motherboards don't run on -48V DC. They run on +12V DC. Power supplies normally take the 110-220V AC power and convert it to 12V DC for the motherboard and 5V DC for peripherals but this causes a loss of efficiency. This Open Rack infrastructure puts the power supply which they're calling a 12V power bar on the rack and supplies the computer with exactly the 12V it needs. In the article they claim they got 50% power savings over a traditional power supply/computer design. While there may be a lot of telecom gear for -48V DC that is not what a computer motherboard needs. It would still require a power supply to convert -48V DC to +12V DC if they had gone that route. This would have increased cost and decreased power efficiency.

Re:Why invent a new standard? (2)

petermgreen (876956) | more than 2 years ago | (#39879523)

Telecom has used 23" racks for years. There are standard adapters already available to mount 19" hardware in a 23" rack. 23" racks are already available in the marketplace.

AIUI they don't want to increase the overall size of the rack so they can fit into standard datacenter floorplans, presumablly this limits the ammount they can widen the server space in the rack without widening the rack itself.

Telecom has been using DC plant for decades and there is a ton of existing 48Vdc equipment on the market.

48V DC was well suited to the needs of telcos at the time who originally used it to directly power POTs lines, that doesn't mean it's appropriate for powering computers.

To prevent currents flowing through metalwork causing ground potential shifts and to limit damage in the event of faults you generally want your computing gear to be isolated from your building power distribution system. This generally implies having an isolating PSU (whether AC-DC or DC-DC) between your building power distribution and your motherboards.

Afaict this 12V system is about connecting multiple servers in a rack to a common rack level PSU, not about changing building power distribution standards. Presumablly 12V was chosen beause it is becoming the standard for powering motherboards (5V and 3.3V are mostly legacy supplies nowadays)

Floor tiles (1)

HockeyPuck (141947) | more than 2 years ago | (#39878587)

Nothing like telling the facilities team "ok, we're going with 21" wide racks and you'll need to replace all the floor tiles as well.

Also floor standing equipment (high end disk arrays and floor standing servers) are also made to the 19" standard (either 1-3 tiles wide and 1-2 tiles deep)

I know... this is for greenfield datacenters...

Re:Floor tiles (1)

Anonymous Coward | more than 2 years ago | (#39878917)

Apparently, the outside widths are the same, so the article says that you don't need to replace floor tiles.

Bigger? (0)

Anonymous Coward | more than 2 years ago | (#39878601)

I'm ok with seeing bigger racks, ifyouknowwhatimean.

wider servers vs 4U box (0)

Anonymous Coward | more than 2 years ago | (#39878619)

"ready for wider servers?"
Bring em!

Why 21? (1)

jon3k (691256) | more than 2 years ago | (#39878697)

I've got 23" racks in my datacenter right now. We use conversion kits to move the rails in to 19" and gives us extra space on the sides for cabling routing. You lose some space but the quality of life in dealing with the cabling makes up for it in our tiny little space (less than 20 racks).

Why not just change all the bolts to SAE (1)

gelfling (6534) | more than 2 years ago | (#39878713)

that way they demand everyone replace every bolt and make a ton of money for doing even less than re racking everything.

Ok, then. (4, Funny)

Impy the Impiuos Imp (442658) | more than 2 years ago | (#39878761)

> Open Compute Developing Wider Rack Standard

Well, programmers have been getting fatter over the years. I suppose this applies to the female ones, too.

Great news! (1, Redundant)

demonbug (309515) | more than 2 years ago | (#39878913)

I think we can all agree, the bigger the rack the better.

(Obvious joke is Obvious)

Re:Great news! (2)

Iniamyen (2440798) | more than 2 years ago | (#39879605)

Especially when they're STACKED!

OK if it's an actual standard (2)

Urban Garlic (447282) | more than 2 years ago | (#39878989)

All will be forgiven if this standard is better than the current scheme. The *only* thing that's consistent about it is the width.

The current scheme has a lot of problems with rail-kits fitting into some racks and not others, because they're too deep, or not deep enough, or because one rack has small threaded holes on the inside of the posts, and another has the big square ones. In my set-up, we only have five racks, and already we're running into problems placing equipment because of differences in the mounting geometry.

Actually, I don't even really need standard mounts, I'd settle for consistent nomenclature -- then at least I could buy adapters, and finally be able to put any piece of equipment in any rack.

12 Volts? (2)

AB3A (192265) | more than 2 years ago | (#39879107)

Why 12 volts? Telephone companies figured out decades ago that 48 volt positive ground systems were more desirable. They reduced the need for heavier copper wire, and they are not likely to be lethal shock hazards (though burns are certainly possible).

Furthermore, every motherboard has multiple switching supplies built in. We have 12 volts, 5 volts, 3.3 volts, 1.8 volts, and probably some adjustable voltages too. Some even have separate regulators for individual parts of the board. We will never be rid of the power supplies. We have simply moved them closer to the processors, memory, I/O, and GPU. Why not design the boards to use -48 volt battery systems as primary inputs so that we can reduce corrosion, use existing infrastructure designs, and keep I^2R losses down?

Oldest standard in computing. (2)

Animats (122034) | more than 2 years ago | (#39879119)

19 inch racks are the oldest standard in computing. The ENIAC used 19 inch racks.

This is really yet another "blade server" scheme. The whole rack is one chassis. Units are on vertically mounted boards with front faces and handles which look like an extra-deep variation on the old Eurocard form factor. That's reasonable enough. It's a lot like 1980s IBM mainframe or 5ESS packaging. Vertically mounted boards are better for airflow, anyway.

It's not about racks which take horizontal boxes like 19 inch rack components, but are slightly wider.

Re:Oldest standard in computing. (1)

swb (14022) | more than 2 years ago | (#39880411)

Maybe that's the whole idea -- develop an "open" blade center scheme that will allow you to mix and match blades without the vendor lock-in that existing blade center systems have.

market opportunity (0)

Anonymous Coward | more than 2 years ago | (#39879133)

Somebody needs to design and produce kits to retro fit 19" rackmountables in a 21" rack.

RTF spec. - benefits and potential issues. (4, Informative)

gstrickler (920733) | more than 2 years ago | (#39879517)

The spec can be downloaded from here [opencompute.org]

At first, I thought this sounded like a stupid idea too. Then, I read the spec. They're not just changing the width of the equipment area, and it's not just an extra 2".

External width is unchanged from the 19" rack standard, it's still nominally 23.6". No replacement of floor tiles or room redesign necessary.

Equipment width is increased from ~17" (on a 19" rack) to 21", it's allows 4" wider equip.

Power is handled in 3 "zones" per tower. Each power zone provides 12.5V DC power on each of 3 independent pairs of power rails, No AC power supply is required for each piece of equipment, but they will need DC-DC converters and VRs to supply the voltages needed for their specific components. That saves some space on each device, and provides a slight improvement in efficiency. Because this is standardized worldwide, there is no need for each device to have different power circuitry for different countries.

Because a zone can have triple power rails, devices can use 1, 2, or 3 power rails to provide whatever level of redundancy is appropriate.

Space for switches is included in each rack, along with power monitoring/reporting circuitry per rack.

Battery backup power can either be built into the power supply for each zone, or supplied from a separate battery rack.

The specification allows for many AC or DC power sources, this is the only significant part of the spec that will vary by country as the power units will need to support the available AC and/or DC supply.

All devices are to be hot-plug compatible.

So, it does have a lot of advantages.

Here are the concerns I have with it:

All power rails appear to be exposed. While they are on the back, this could be a significant safety (personnel and/or fire) issue. Considering that you can up to 500A @ 12.5V DC running through the zone power rails, and potentially more for the main cabinet DC power rails, exposed seems like a bad idea.

The standard allows depths from 36" to 48". With the way devices connect to power rails on the back, it looks like this means you will need to use devices designed for the specific depth of your rack, or use a shim to extend the device to match the depth of the rack. I believe they should standardize on one, or at most 3 depths, and have a standard set of shims to connect the devices designed for the shorter depths to fit the deeper racks.

METRIC (1)

bussdriver (620565) | more than 2 years ago | (#39880255)

New specs should all be metric; it is not modern if it is using imperial measurement. The new 21" should be 534mm.
Keep the outside stuff the same but convert it all into metric.

Re:METRIC (1)

gstrickler (920733) | more than 2 years ago | (#39880357)

The specs are in metric, with US units for the convenience of those who are metric impaired. You should try reading them before posting.

Re:METRIC (1)

bussdriver (620565) | more than 2 years ago | (#39880447)

No time; but the summary was not in metric either. Some of us do not use that crap system.

12 volt bad. Also, I don't think it's broke... (1)

Copperhamster (1031604) | more than 2 years ago | (#39879525)

12 volts is horrid. Really. I have a friend that works in the car audio 'boom boom' industry and he really laments 12 volts. He has to run 0 gauge wire for items that bolt onto a fold down back seat of an SUV... how big a bus bar will we need for a full rack of 12 volt junk?

The limiting safety factor on voltage is breakdown of insulation. The limiting safety factor on current is wire diameter (and to a lesser extent, length). We've converted a good deal of our AC to 240 just to increase wattage capacity. Don't go the wrong way guys.

Also, if you are redefining racks:
23" already exists.
If you must make a new size, make it metric. Also make the rack units metric. And saying 1RU = 2.54 cm is not making it metric.
If you are standardizing everything else, come up with one (not neccessarily new) standard for 'how things are connected to the rack' (one thread, one style hole, one style thing to adapt thread to hole) so I don't have a drawer full of 18 different types of hardware for the things. (ok is this rack 8-32 or 10-32 or 12-24 or M5 or M6. Oh wait the rack kit wants square holes so I need to put this server over in that rack instead... but the nas array wants round unthreaded holes so it has to go across the room)

12 Volts for a better life! (1)

beltsbear (2489652) | more than 2 years ago | (#39880185)

Support for this standard provided by the copper mining and manufacturing association.
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