Forgot your password?
typodupeerror
Facebook Hardware IT

Open Compute Developing Wider Rack Standard 237

Posted by timothy
from the so-many-to-choose-from dept.
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."
This discussion has been archived. No new comments can be posted.

Open Compute Developing Wider Rack Standard

Comments Filter:
  • by alphatel (1450715) * on Thursday May 03, 2012 @10:57AM (#39878403)
    So put the server power supply on the outside, basically.
    • If I understood that correctly, it is not only a matter of putting the power suply outside, but also of making your heat dissipators wider, and space things better inside the servers.

  • metric? (Score:5, Insightful)

    by SkunkPussy (85271) on Thursday May 03, 2012 @10:58AM (#39878411) Journal

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

    • Re: (Score:3, Insightful)

      by Anonymous Coward

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

      • Re:metric? (Score:5, Funny)

        by Christian Smith (3497) on Thursday May 03, 2012 @11:25AM (#39878787) Homepage

        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? (Score:5, Insightful)

          by Anonymous Coward on Thursday May 03, 2012 @11:40AM (#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: (Score:3, Informative)

            by ChatHuant (801522)

            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? (Score:5, Insightful)

              by Anonymous Coward on Thursday May 03, 2012 @01:53PM (#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.

              • by Grishnakh (216268)

                You also don't know if that 5 means J or mJ or cJ or kJ or MJ. The SI system is always pushing you to use prefixes so you don't have to write out a lot of zeros.

            • 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.
            • by dj245 (732906)
              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 confu
            • 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.

              Flawed logic. Units always need to be labeled. Here's a metric length for you 5.5

              You know it's metric and a length, therefore, it's in meters. But is is nm, mm, cm, m, km? Without labeling, you have no idea what the units are.

              Unless you want to eliminate all the si prefixes and list everything as decimal gm, m, l, etc. Of course, that's as absurd proposition, making your statement absurd and incorrect.

            • by Grishnakh (216268)

              But units wouldn't need to be labeled if everybody used the same system.

              This is stupid. Units ALWAYS must be labeled, even with the SI system. How do you know whether you're dealing with mm, cm, m, dm, Mm, etc? Or V, mV, uV, etc.? The SI system is very big on using prefixes to show order of magnitude, and if you don't use unit labels, you won't know what order of magnitude you're dealing with. You can assume it, but we've all seen what happens when you make wrong assumptions.

              • by ChatHuant (801522)

                This is stupid. Units ALWAYS must be labeled, even with the SI system

                Maybe in technical documents, but that's not true in many cases. It all depends on having the proper context. If somebody asks "how old are you", answering "35" is quite unambiguous, because of the shared context. You don't need to explain what units you're using - nobody would suspect you mean 35 weeks or hours (or if you're Han Solo, parsecs). The Lockheed problem was caused by the existence of 2 different contexts, Imperial and metric, close enough to be easily confused. If the Imperial units weren't eve

          • Re:metric? (Score:4, Insightful)

            by Shompol (1690084) on Thursday May 03, 2012 @05:09PM (#39882981)

            Secondly SI isn't always the best unit of measurement for performing calculations.

            While Imperial units are always the worst.

      • 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? (Score:4, Funny)

        by MetalliQaZ (539913) on Thursday May 03, 2012 @11:40AM (#39879015)

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

    • Re:metric? (Score:4, Insightful)

      by richardkelleher (1184251) on Thursday May 03, 2012 @12:19PM (#39879449) Homepage

      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.

      • by jeffmeden (135043)

        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 (eve

      • 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: (Score:2, Insightful)

          Imperial units are much easier in some cases, being divisible by a whole bunch of numbers not easily divisible on metric. What happens when you have a one meter (M) whole unit, that you need to divide into 1/3? The nice thing about imperial units, is that typically they are easily divisible by 2, 3, 4 (6, 8, 12) while metric units are not. 1/3 of a meter is how much exactly? 2/3 of a liter?

          Metric is nice and elegant, so don't get me wrong, but imperial has its own elegance.

          • 1/3 of a meter is how much exactly? 2/3 of a liter?

            333.33333... mm and 666.66666... ml respectively. Simple.

            How much is 1/3 of an ounce? 1/5 of a gallon? 2/3 of a pound? And is that an avoirdupois, troy, or apothecary's pound?

            Methinks you have asked the wrong questions, son.

          • by AmiMoJo (196126)

            What happens when you have a one meter (M) whole unit, that you need to divide into 1/3?

            What happens when you need to divide 1ft into 1/5th? You can cherry-pick random examples of computational inconvenience all day, but metric still has two advantages. Firstly it is easy to plug into a calculator or spreadsheet, making all computation easier. Secondly if you are designing something you can simply use 1200mm instead of 12 inches to get the same divisions in addition to the ease of decimal.

          • by dmatos (232892)

            1/3 of a metre: 33 1/3cm, or 333 1/3mm. Choose as many significant digits as you like.
            2/3 of a litre: 666 2/3 mL.

            How much is one fifth of a yard? One tenth of a foot? One eleventh of a hogshead? half a slug?

    • Re:metric? (Score:5, Insightful)

      by David Chappell (671429) on Thursday May 03, 2012 @01:32PM (#39880095) Homepage

      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.

      • by jeffmeden (135043)

        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!

      • by ExploHD (888637)

        Better to just call them 5334 mm racks.

        I preffer 1337 mm racks.

    • by Jamu (852752)
      The inch is a metric unit. As a consequence of the yard being defined as 0.9144 meters, the inch is exactly 25.4 mm. The Open Rack server slots will be 5.334 meters. Maybe they should round down to 5.333... meters.
  • by Hognoxious (631665) on Thursday May 03, 2012 @11:01AM (#39878453) Homepage Journal

    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?

    • 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

    • by Grishnakh (216268)

      I haven't read TFA (this is Slashdot; we don't do that sort of thing), but maybe they're proposing making the units thinner too. If "1U" is thinner with the wider standard than with the 19" standard, then you should be able to fit more servers into a rack, making up for the increased width.

  • 2" shim market (Score:5, Insightful)

    by RichMan (8097) on Thursday May 03, 2012 @11:01AM (#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.

    • by istartedi (132515)

      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.

      • 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.

    • by MarkGriz (520778)

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

    • by nschubach (922175)

      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])

  • by darthcamaro (735685) on Thursday May 03, 2012 @11:06AM (#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.
    • by IGnatius T Foobar (4328) on Thursday May 03, 2012 @12:16PM (#39879415) Homepage Journal
      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.
  • already have 23" (Score:2, Interesting)

    by Anonymous Coward

    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.

  • by Anonymous Coward on Thursday May 03, 2012 @11:06AM (#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.

    • 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.

      • 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

      • 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.
        • by RulerOf (975607)

          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!

        • by Grishnakh (216268) on Thursday May 03, 2012 @03:29PM (#39881273)

          They should just dump the -12V requirement. They've had chips available for years that can supply +/-12V for RS232 ports; I believe the MAX232 from Maxim is one of them: you connect it to 5V data lines from your microcontroller, give it 5V for power, add in four capacitors, and it outputs +/-12V RS232 signals. I was using this chip back in the late 90s for embedded equipment that needed RS232 connectivity so we wouldn't need a power supply with -12V.

          They should also dump the 3.3V requirement. AFAIK, that's only used for SATA hard drives, and even there most don't use it because they couldn't count on people actually having 3.3V-compliant power supplies, as many users were installing the (then-new) SATA drives into older computers and using Molex-to-SATA power adapters. 3.3V has a huge drop over any distance, so it makes much more sense to just use a DC-to-DC convertor at the point of use to convert 12V to 3.3V. Now that even CPUs want 12V instead of 5V, and high-end video cards have their own 12V connectors, it seems to me they should just dump all the other requirements altogether, and make a PC power supply only produce +12V, and have the motherboard and drives use their own DC-to-DC converters to produce whatever voltages they require.

    • by hjf (703092)

      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?

      • by afidel (530433)
        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]
        • by tlhIngan (30335)

          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. 500

          • by afidel (530433)
            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.
            • by rev0lt (1950662)

              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.

              • by afidel (530433)
                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
          • by Grishnakh (216268)

            Telecoms use 48V (actually -48V) because they've used it for many decades, long before silicon ICs were invented.

            That said, I really wonder how the losses would compare for using 48V and using DC-to-DC converters to produce 12V on each server. Also, how would the cost compare? Copper bus bars are expensive, and copper is getting more expensive all the time; before long, people will be thinking of using silver instead (exaggerating, but only slightly).

        • by sjames (1099)

          Copper is expensive and heavy. I would rather see 48v supplied and lighter bus bars.

          Switching power supplies can be quite simple and efficient if they don't need PFC or boost capability. That suggests DC input above the maximum output voltage.

    • by mpoulton (689851)
      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.
    • ... the AC post should be nominated for one of the best ever

    • by couchslug (175151)

      Fracture markets for vendor-lock win!

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

    • 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 f

    • Further, why 12Vdc?

      Because that is what the current servers actualy use. Why put a 48V bus on the rack if you'll still need to convert it to 12V?

      • by Grishnakh (216268)

        Because the losses over even 8 feet of rack height can be significant at these current levels. With 48V, you have 1/16 the loss, and you can use smaller bus bars. Copper is getting to be extremely expensive these days, and 48/12 DC-to-DC converters are 97% efficient these days. Or, if this is going to be a whole new standard, why not just run 48V to the motherboards and drives, and convert it to 3.3/5/1.8 or whatever directly? Getting 48V drives may or may not be realistic, but getting motherboards desi

    • Yup, that's what I was thinking - I used to work in television years ago, and I seem to recall that we had to use adapters when fitting stuff that was meant for "standard" (19") racks.

  • 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...

  • by jon3k (691256)
    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).
  • that way they demand everyone replace every bolt and make a ton of money for doing even less than re racking everything.

  • Ok, then. (Score:4, Funny)

    by Impy the Impiuos Imp (442658) on Thursday May 03, 2012 @11:23AM (#39878761) Journal

    > 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! (Score:2, Redundant)

    by demonbug (309515)

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

    (Obvious joke is Obvious)

  • by Urban Garlic (447282) on Thursday May 03, 2012 @11:38AM (#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.

  • by AB3A (192265) on Thursday May 03, 2012 @11:45AM (#39879107) Homepage Journal

    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?

  • by Animats (122034) on Thursday May 03, 2012 @11:46AM (#39879119) Homepage

    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.

    • by swb (14022)

      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.

  • by gstrickler (920733) on Thursday May 03, 2012 @12:27PM (#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.

    • 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.

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

HELP!!!! I'm being held prisoner in /usr/games/lib!

Working...