6 ms·

No mention of power requirements/allowances? I recall some gpus a while back being a big deal because they just squeezed into the power envelope allowed by pcie

• SAI_Peregrinus 9y ago
  High-end GPUs have a second or even third power connector, direct to the PSU. The power supplies to support them have dedicated 12V rails for each. The case you're remembering was due to trying to build cards down to a lower price by not including this connector and running very near the max allowed power that can be taken from the PCI slot connector. IIRC When combined with cheap motherboards and power supplies it resulted in failures. The 6-pin PCIE power connectors can handle 75W, the 8-pins 150W, according to the specs. Some video cards have multiples of these connectors, to allow for very high power consumption. If more power is needed they'll just add more and require a bigger power supply.
  • blattimwind 9y ago
    GPU servers nowadays use proprietary form factors for GPUs anyway (like SXM2).
    • cameldrv 9y ago
      I'd be curious to hear who is using servers with the proprietary form factor GPUs. The prices for datacenter vs. gamer versions of the same GPUs have gotten really out of whack, where a 1080ti is $700, and a P100 is $7000, and at least on FP32, they have the same performance. From what I hear, most all of the major DL research labs are using 4U servers with 8 of either the 1080ti or the Titan Xp rather than the SXM2 Teslas. On the other hand, all of the cloud providers seem to be sticking with the Tesla products, and pricing GPU instances commensurately. I really wish there were a cloud provider that offered instances with the gamer cards in them so that companies in the DL field weren't effectively forced to buy and manage their own hardware.
      • sacheendra 9y ago
        You can use the AWS g2 instances.
      • verall 9y ago
        A P100 has a gp100 with nvlink, hbm2, and a 610mm die, while a 1080ti or titan Xp has a gp102 with gddr5x and 471mm die. It is not like quadro vs geforce where they both run on a gp102 with different drivers, the gp100 is considerably physically larger and has a much smaller userbase. I would be very surprised if they have the same fp32 performance in real world situations.
        • wmf 9y ago
          OK, so let's compare eight GP102s against one GP100. Is there any metric where GP100 wins?
          • ori_b 9y ago
            Power consumption and space consumption.
      • tanderson92 9y ago
        Right, well, people who need FP64 aren't going to be satisfied with the 1080ti so that is the answer. See this comment of mine: https://news.ycombinator.com/item?id=14597486 https://news.ycombinator.com/item?id=14597486
        • matt4077 9y ago
          I actually think FP16 performance is more of a factor for those choosing the Tesla platform.
          • tanderson92 9y ago
            You mean for the Volta architecture, surely? I'm talking about currently available hardware.
    • shaklee3 9y ago
      That's not really true. The first card to introduce this form factor was the Pascal p100. It is still priced way out of most people's price range compared to the older cards. They also have pcie versions of that card, which perform close to the same.
  • hirsin 9y ago
    Ah, thank you, that was it! I mistakenly believed there was a connection between the power input to the card and the amount it could send out over the lanes.
  • bryanlarsen 9y ago
    The PCIE spec also says that the maximum power supplied via external connectors is 225W. This is so that system makers know how big to size their power supplies to so that they can claim to support a maximally spec'd PCIE board. Obviously a board can require more external power, but board makers do generally try to stay below 300W.
    • wtallis 9y ago
      It seems like system integrators all use either 300-400W PSUs (for consumer systems that come with a single GPU that's seldom top of the line), or they use 1200W or dual-900W PSUs for the high-end workstations to ensure they can handle 4 top of the line GPUs. Meanwhile, the retail PSU market for enthusiasts building their own PCs is dominated by 500-850W models that are way oversized for almost all ordinary desktop usage, but guarantee safe headroom for the few users who do extreme overclocking or actually bother with multiple GPUs.
      • lathiat 9y ago
        Something most people ignore is that many of these 500-850W enthusiast PSUs have higher efficiency and often near-silent or even no-fan performance at the usually used 50-200W power usage range.
  • ClassyJacket 9y ago
    There have even been graphics cards that had their own power plug that you plugged directly into the wall!