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Render Node Considerations

How To: Building Your Own Render Farm
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If you're looking at installing a large number of render nodes in your home, you need to consider both power and cooling. We’re talking about multiple systems sitting in an enclosed space, which will consume a lot of power and generate significant heat in a very small area. You should consequently think about how many nodes will fit in the space allotted.

For a freelancer using a home studio, you may actually be tempted to build 10 identical boxes, but keep power consumption in mind. The electrical standard in U.S. homes is 110 V at 15 amps, which means 1,650 W is the maximum for a typical circuit. Some houses may have 20 amp breakers, which gives you a little more leeway, but putting 10 nodes on a circuit means you'd better build extremely efficient systems. If someone turns on a hair dryer on the same circuit, you'll hear the breaker flip pretty quickly.

If you really need to put 10 nodes in your home, you may want to split them up into two groups of five. Those five may still consume most of the power available to the circuit they are on. However, keep in mind that with a low thermal design power (TDP) processor, these systems should only consume about 140 W of power apiece at 100% utilization, depending on the actual processor used, motherboard, chipset, and hard drive. Across 10 systems, that’s 1,400 W, which is still very close to the maximum yield of an average household line.

After power, your next concern should be cooling. Several 1U computer systems placed in a tight space will generate plenty of warm air behind the boxes. In order to boost airflow efficiency, most IT departments maintain a hot aisle/cold aisle layout. With a hot aisle/cold aisle layout, the systems draw in cool air from one side, which is then exhausted out the other side. To a lesser degree, you can apply this data center concept to your setup at home to handle the airflow for several nodes. Make sure, for example, that there is cool airflow at the front of the systems and a way to evacuate the air behind them (don't put the back of your rack against the wall).

You also need to worry about redundancy. If one node goes down, you could potentially lose that portion of your render farm. If you can spare the expense, you could build a spare node to swap in as needed, but then you have to suppress the urge to use it as a node and defeat the purpose of having it as a spare.

Serving Files

With multiple render nodes, it is important host the files for your software somewhere else other than on your production workstation, especially if you're trying to use the workstation while the other systems render. It is thus a good idea to either buy a network attached storage (NAS) box or build a small Linux server to handle the file-hosting chores to keep your workstation from being taxed by serving files for other systems.

Depending on personal preference, you can either "publish" the files to the server before starting a render or you can actually work with the files from the server all the time. The first option means your workstation will have fast local access when interactivity is important, while the second option means you will avoid missing files and broken internal links when moving things to the server. Troubleshooting these kinds of render problems can get very tedious, and if you're not careful, you can end up spending hours rendering an entire scene only to discover afterward that a texture in the scene was either missing or not the correct version.

If you’re not currently working with your 3D files on a remote system or file server, then you have to move those files to the server and go through and fix these potential problems. After doing that, it would be a good idea to get into the habit of working with all of your scenes remotely so that the content is automatically on the remote file system, allowing you to avoid having to move the scenes over to the server when rendering tasks are performed.

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Top Comments
  • 13 Hide
    MonsterCookie , July 17, 2009 1:33 PM
    Due to my job I work on parallel computers every day.
    I got to say: building a cheapo C2D might be OK, but still it is better nowadays to buy cheap C2Q instead, because the price/performance ratio of the machine is considerably better.
    However, please DO NOT spend more than 30% of you money on useless M$ products.
    Be serious, and keep cheap things cheap, and spend your hard earned money on a better machine or on your wife/kids/bear instead.
    Use linux, solaris, whatsoever ...
    Better performance, better memory management, higher stability.
    IN FACT, most real design/3D applications run under unixoid operating systems.
Other Comments
  • 4 Hide
    Draven35 , July 17, 2009 9:14 AM
    People have been saying that for several years now, and Nvidia has killed Gelato. Every time that there has been an effort to move to GPU-based rendering, there has been a change to how things are rendered that has made it ineffective to do so.
  • 3 Hide
    borandi , July 17, 2009 9:43 AM
    With the advent of OpenCL at the tail end of the year, and given that a server farm is a centre for multiparallel processes, GPGPU rendering should be around the corner. You can't ignore the power of 1.2TFlops per PCI-E slot (if you can render efficiently enough), or 2.4TFlops per kilowatt, as opposed to 10 old Pentium Dual Cores in a rack.
  • 4 Hide
    Draven35 , July 17, 2009 9:53 AM
    Yes, but it still won't render in real time. You'll still need render time, and that means separate systems. i did not ignore that in the article, and in fact discussed GPU-based rendering and ways to prepare your nodes for that. Just because you may start rendering on a GPU, does not mean it will be in real time. TV rendering is now in high definitiion, (finished in 1080p, usually) and rendering for film is done in at least that resolution, or 2k-4k. If you think you're going to use GPU-based rendering, get boards with an x16 slot, and rsier cards, then put GPUs in the units when you start using it. Considering software development cycles, It will likely be a year before a GPGPU-based renderer made in OpenCL is available from any 3D software vendors for at least a year (i.e. SIGGRAPH 2010). Most 3D animators do not and will not develop their own renderers.
  • 0 Hide
    ytoledano , July 17, 2009 11:31 AM
    While I never rendered any 3d scenes, I did learn a lot on building a home server rack. I'm working on a project which involves combinatorial optimization and genetic algorithms - both need a lot of processing power and can be easily split to many processing units. I was surprised to see how cheap one quad core node can be.
  • 0 Hide
    Draven35 , July 17, 2009 11:39 AM
    Great, thanks- its very cool to hear someone cite another use of this type of setup. Hope you found some useful data.
  • 13 Hide
    MonsterCookie , July 17, 2009 1:33 PM
    Due to my job I work on parallel computers every day.
    I got to say: building a cheapo C2D might be OK, but still it is better nowadays to buy cheap C2Q instead, because the price/performance ratio of the machine is considerably better.
    However, please DO NOT spend more than 30% of you money on useless M$ products.
    Be serious, and keep cheap things cheap, and spend your hard earned money on a better machine or on your wife/kids/bear instead.
    Use linux, solaris, whatsoever ...
    Better performance, better memory management, higher stability.
    IN FACT, most real design/3D applications run under unixoid operating systems.
  • 0 Hide
    ricstorms , July 17, 2009 1:38 PM
    Actually I think if you look at a value analysis, AMD could actually give a decent value for the money. Get an old Phenom 9600 for $89 and build some ridiculously cheap workstations and nodes. The only thing that would kill you is power consumption, I don't think the 1st gen Phenoms were good at undervolting (of course they weren't good on a whole lot of things). Of course the Q8200 would trounce it, but Intel won't put their Quads south of $150 (not that they really need to).
  • 0 Hide
    eaclou , July 17, 2009 1:50 PM
    Thanks for doing an article on workstations -- sometimes it feels like all of the articles are only concerned with gaming.

    I'm not to the point yet where I really need a render farm, but this information might come in handy in a year or two. (and I severely doubt GPU rendering will make CPU rendering a thing of the past in 2 years)

    I look forward to future articles on workstations
    -Is there any chance of a comparison between workstation graphics cards and gaming graphics cards?
  • 1 Hide
    cah027 , July 17, 2009 1:52 PM
    I wish these software companies would get on the ball. There are consumer level software packages that will use multiple cpu cores as well as GPU all at the same time. Then someone could build a 4 socket, 6 GPU box all in one that would do the work equal to several cheap nodes!
  • -1 Hide
    sanchz , July 17, 2009 3:22 PM
    Correct me if I'm wrong, but wouldn't 30 million hours be 30,000,000/24 = 1,250,000 days which would in turn be 1,250,000 / 365 = 3,425 YEARS!!! O.o
    Please someone clarify this. How could they render a movie for 3,000 years? Did they have this render farms hidden in Egypt??
  • -2 Hide
    nemi_PC , July 17, 2009 3:27 PM
    Some thoughts for small nodes:
    1) Cases cablable of taking a 2 slot grpahics card woudl future proff setting up anode at this time in case GPU rendering does become applciable over the lifetiem of the node. So (m)ATX cases not rack mounts
    2) Resale of a (m)ATX "reglaur" looking desktop a few years down he road to "home users" is easier than a rack mount server. So should factor that into the value.
    3) With 500-1TB being the sweet spot for Gb/$ I would go with those drives and use the render node also as a distributed (redundant) back up solution , this address where are you going to store all your work over the years.
  • 2 Hide
    eyemaster , July 17, 2009 3:33 PM
    I'm with you sanchz. But I think they mean per single processor. Say, if you had a common desktop computer and tried to render the whole transformers 2 movie, it would take thousands of years. If you have 10000 processors doing the job, you can do it within a year or less.
  • 0 Hide
    mlcloud , July 17, 2009 3:33 PM
    sanchzCorrect me if I'm wrong, but wouldn't 30 million hours be 30,000,000/24 = 1,250,000 days which would in turn be 1,250,000 / 365 = 3,425 YEARS!!! O.oPlease someone clarify this. How could they render a movie for 3,000 years? Did they have this render farms hidden in Egypt??


    What do you think the meaning of parallel processing is? Doing a lot of that work at once, right? If we have a huge render farm of 5000+ processors, we cut down that time to less than a year, wouldn't we?

    Of course, a lot of that depends how fast each processor in the render farm is, but the general public won't care about that; just give 'em the huge numbers and don't tell them you were using 1.6ghz celery's in your render farms.
  • -1 Hide
    one-shot , July 17, 2009 4:10 PM
    Hmmm. The standard electrical voltage for residential dwellings (United States) on a 120/240V two phase installation is plus or minus 5% of 120V, not the 110V which is mostly stated. So 15A * 120V = 1800VA or Watts, not 15 * 110V.
  • -5 Hide
    ossie , July 17, 2009 4:41 PM
    In view of eventual future GPU offloading, at least a 3U case for 4x2slot-PCIe GPUs would be necessary, so the upgradeability of 1U cases is limited to one 1slot GPU. But such a monster would get easy over 1kW, posing more challenges for power supply and cooling (generated noise left apart).
    As MonsterCookie pointed already out, use some good scaling multi-processor/-node OS for good distributed performance (m$ doesn't apply).

    Finally a decent article on TH... almost without the usual vi$hta or $even (aka vi$hta sp2+) m$ pu$hers behind.
    What? xpire x64 is working for TH? almost unbelievable...
    Also, none of the usual m$ fankiddie and gamer comments, (at least) till now... :) 
  • 0 Hide
    dami , July 17, 2009 5:02 PM
    Another example, getting out of the computer jargon...

    If a task took 100 man hours, that means it took 2 guys 50 hours each to do something. If you did that with 10 guys, it would take each man 10 hours of work. There is a point of diminishing efficiency, which is mentioned in the article. The extreme to this is, it would take 100 men, 1 hour of work to complete the same task. The efficiency has been drasticly reduced.

    This is whats being done in these rendering farms. A bunch of processors are put together, tasked with a job, and they belt out the results. If you did that with just one processor, it would take the 3k years in egypt to come up with a result.
  • -1 Hide
    Anonymous , July 17, 2009 5:11 PM
    borandiAnd soon they'll all move to graphics cards rendering. Simple. This article for now: worthless.

    I do agree with graphics card rendering,but don't think this article is worthless!

    When I read about xeons, I also read about AMD making similar, low power processors like that (45nm or lower?,and a TDP of around 65W, which is 30W lower than their previous processor line).
    It might not be beneficial to buy xeons, but perhaps it might when going with AMD.
  • -8 Hide
    aspireonelover , July 17, 2009 5:17 PM
    I rather spend the money on helping developing countries. (I know this has nothing to do with farm render and stuff but the amount of money they've spent on these machines is an incredible amount)
    Like buy a few XO netbooks for the developing countries, and sponsor lots of children.
  • 0 Hide
    Anonymous , July 17, 2009 6:15 PM
    How about network booting the cluster - we have found it easier to manage upgrades/patches as you just need to reboot the nodes that need upgrading. Also makes each node a little cheaper and saves a fair bit on power consumption.
    Another idea we have been playing with is using cheap USB keyfobs either as system drives or to persist config data etc. - much faster boot times, very low power consumption and great MTTF.
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