Energy and HPC

AVX/FP intensive applications are known to be real power hogs. How bad can it get? We used the OpenFOAM test and measured both average and maximum power (the 95th percentile). Average power tells us how much energy will be consumed for each HPC job while maximum power is important as you have to allocate enough amps to your rack to feed your HPC server/cluster.

HPC maximum performance power consumption

This confirms there is more going on than just the fact that our "Wildcat Pass" server consumes more than the Supermicro server in this test. At peak, the Xeon E5-2699 v3 consumes almost 450W (!!) more than at idle. Even if we assume that the fans take 100W, that means that 350W is going to the CPUs. That's around 175W per socket, and even though it's measured at the wall and thus includes the Voltager regulators, that's a lot of power. The Xeon E5-2699 v3 is a massive powerhouse, but it's one that needs a lot of amps to perform its job.

Interestingly, the Xeon E5-2695 v3 is also using more power than all previous Xeons. The contrast with our Drupal power measurements is very telling. In the Drupal test, the CPU was able to let many of the cores sleep a lot of the time. In OpenFOAM, all the cores are working at full bore and the superior power savings of the Haswell cores deep sleep states do not matter much. But which CPU is the winner? To make this more clear, we have to calculate the actual energy consumed (average power x time ran).

Total HPC Energy Consumption per job

When we look at how much energy is consumed to get the job done, the picture changes. The old Xeon "Sandy Bridge EP" is far behind. It is clear that Intel has improved AVX efficiency quite a bit. The low power Xeon E5-2650L v3 is a clear winner. In second place, the fastest Xeon on the planet actually saves energy compared to the older Xeons, as long as you can provide the peak amps.

HPC: OpenFoam LRDIMMs: Capacity and Real World Performance
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  • MorinMoss - Friday, August 9, 2019 - link

    Hello from 2019.
    AMD has a LOT of ground to make up but it's a new world and a new race
    https://www.anandtech.com/show/14605/the-and-ryzen...
  • Kevin G - Monday, September 8, 2014 - link

    As an owner of a dual Opteron 6376 system, I shudder at how far behind that platform is. Then I look down and see that I have both of my kidneys as I didn't need to sell one for a pair of Xeons so I don't feel so bad. For the price of one E5-2660v3 I was able to pick up two Opteron 6376's.
  • wallysb01 - Monday, September 8, 2014 - link

    But the rest of the system cost is about the same. So you get 1/2 the performance for a 10% discount. YEPPY!
  • Kevin G - Monday, September 8, 2014 - link

    Nope. Build price after all the upgrades over the course of two years is some where around $3600 USD. The two Opterons accounted for a bit more than a third of that price. Not bad for 32 cores and 128 GB of memory. Even with Haswell-E being twice as fast, I'd have to spend nearly twice as much (CPU's cost twice as much as does DDR4 compared to when I bought my DDR3 memory). To put it into prespective, a single Xeon E5 2999v3 might be faster than my build but I was able to build an entire system for less than the price Intel's flagship server CPU.

    I will say something odd - component prices have increased since I purchased parts. RAM prices have gone up by 50% and the motherboard I use has seemingly increased in price by $100 due to scarcity. Enthusiast video card prices have also gotten crazy over the past couple of years so a high end video card is $100 more for top of the line in the consumer space.
  • wallysb01 - Tuesday, September 9, 2014 - link

    Going to the E5 2699 isn’t needed. A pair of 2660 v3s is probably going to be nearly 2x as fast the 6376, especially for floating point where your 32 cores are more like 16 cores or for jobs that can’t use very many threads. True a pair of 2660s will be twice as expensive. On a total system it would add about $1.5K. We’ll have to wait for the workstation slanted view, but for an extra $1.5K, you’d probably have a workstation that’s much better at most tasks.
  • Kevin G - Friday, September 12, 2014 - link

    Actually if you're aiming to double the performance of a dual Opteron 6376, two E5-2695v3's look to be a good pick for that target according to this review. A pair of those will set you pack $4848 which is more than what my complete system build cost.

    Processors are only one component. So while a dual Xeon E5-2695v3 system would be twice as fast, total system cost is also approaching double due to memory and motherboard pricing differences.
  • Kahenraz - Monday, September 8, 2014 - link

    I'm running a 6376 server as well and, although I too yearn for improved single-threaded performance, I could actually afford to own this one. As delicious as these Intel processors are, they are not priced for us mere mortals.

    From a price/performance standpoint, I would still build another Opteron server unless I knew that single-threaded performance was critical.
  • JDG1980 - Tuesday, September 9, 2014 - link

    The E5-2630 v3 is cheaper than the Opteron 6376 and I would be very surprised if it didn't offer better performance.
  • Kahenraz - Tuesday, September 9, 2014 - link

    6376s can be had very cheaply on the second-hand market, especially bundled with a motherboard. Additionally, the E5-2630 v3 requires both a premium on the board and DDR4 memory.

    I'd wager you could still build an Opteron 6376 system for half or less.
  • Kevin G - Tuesday, September 9, 2014 - link

    It'd only be fair to go with the second hand market for the E5-2630v3's but being new means they don't exist. :)

    Still going by new prices, an Opteron 6376 will be cheaper but roughly 33% from what I can tell. You're correct that the new Xeon's have a premium pricing on motherboards and DDR4 memory.

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