Power Consumption

The most power hungry 2.93GHz Nehalems are sold in the desktop market (130W TDP), while the "greenest" ones are sold in the server market (95W). It is clear that Intel understands that performance alone is not good enough and the performance/watt metric is getting more popular each day. A direct power comparison was not possible, as the servers are too different: different power supplies, form factors, and so on. Therefore, we tested in a different way. First, we tested the server with two CPUs. Second, we tested the server with one CPU, while we kept the number of DIMMs the same. That way we could subtract both numbers and calculate the difference that one CPU made. It is not very accurate, but it's good enough to get a rough idea. The CPUs were running at about 80% CPU load, running the DVD-store benchmark for 10 minutes. Below you find the average power consumption.
 
Power Consumption

The method we used does not allow us to determine the absolute idle power numbers very accurately, but it seems that Xeon X5570 consumes 8W to 10W less when running at idle. Again, all these numbers have a pretty high margin of error, but they are accurate enough to say that the Opteron 2384 consumes quite a bit less at full load while the latest Xeon is clearly the winner when you are running idle. If your application is running close to idle most of the time, with a few spikes at some parts of the day, the Xeon is the performance/watt champion.

The only question is what happens if the server is running most of the time at relatively high load (for example thanks to virtualization)? Then we have to remember that the CPU is only part of a complete server. Let us assume that the Nehalem server consumes 320W (which is close to what we measured). A similar AMD Opteron server can then save about 18W per CPU, and 1W per DIMM as high speed DDR3 is a bit more power hungry than DDR2 (which runs at a lower speed). We assume that we use six DIMMs per CPU.

Power Comparison
  Power consumption Performance Performance/Watt
Intel X5570 2.93GHz 320 116399 363.7469
AMD 270 70034 259.3852

We could say that the Nehalem is winning by a margin of about 40%. Now, it is clear that the absolute winner is difficult to determine; it all depends on your applications. Still, it is clear that when you compare the best Intel and AMD CPUs, the best performance/Watt figures come from Intel by pretty large margin.

HPC Market Pricing
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  • Veteran - Wednesday, April 1, 2009 - link

    I didn't mean to offend you, because i can imagine how much time it takes to test hardware properly. And i personally think that OLTP/OLAP testing is very innovative and needed. Because otherwise people would have no idea what to buy for servers. You cannot let you server purchase be influenced with meaningless (for servers) simple benchmarks like 3D 2006/Vantage/FPS test etc.
    You guys always are doing a great a job at testing any piece of hardware, but it is just feeling to much biased towards Intel. For example, at the last page of this review you get a link to Intel resource Center (in the same place as the next button). If you have things like that, you are not (trying to be) objective IMO.
  • JohanAnandtech - Wednesday, April 1, 2009 - link

    Thank you for clarifying in a very constructive way.

    "the last page of this review you get a link to Intel resource Center"

    I can't say I am happy with that link as it creates the wrong impression. But the deal is: editors don't involve in ad management, ad sales people don't get involved when it comes to content.

    So all I can say is to judge our content, not our ads. And like I said, it didn't stop us from claiming that Shanghai was by far the best server CPU a few months ago. And that conclusion was not on many sites.
  • Veteran - Wednesday, April 1, 2009 - link

    Thanks for clarrifying this matter.

    But ad sales people should know this creates the wrong impression. A review site (for me at least) is all about objectivity and credibility. When you place a link to Intel's Resource Center at the end of every review, it feels weird. People on forums already call Anandtech, Inteltech. And i don't think this is what you guys want.

    I always liked Anandtech since when I was a kid, and I still do. You guys always have one of the most in-depth reviews (especially on the very technical side) and I like that. But you guys are gaining some very negative publicity on the net.
  • BaronMatrix - Tuesday, March 31, 2009 - link

    Unfortunately, I don't buy from or recommend criminals.
  • carniver - Wednesday, April 1, 2009 - link

    AMDZone is the biggest joke on the internet. I just went there to see how the zealots like abinstein are still doing their damage control; just like before he went on rambling how the Penryn is still weak against Shanghai, and the old and tired excuses like how if people all bought AMD they can drop in upgrades etc etc. ZootyGray...he's the biggest joke on AMDZone. None of them had the mental capacity to accept AMD has been DEFEATED, which is disappointing but funny to say the least
  • duploxxx - Wednesday, April 1, 2009 - link

    It's not just AMDZone, you are just the opposite. Its like in Woodcrest and conroe times, it's not because the high-end cpu is the best of all that the rest of the available cpu's in the line is by default better. It's all about price performance ratio. Like many who were buying the low-end and think they had bought the better system, well wrong bet.

    As mentioned before, why not test the mid range that is where the sales will be. Time to test 5520-5530 against 2380-82 after all those have the same price.
  • carniver - Wednesday, April 1, 2009 - link

    Your argument is valid, however, it just so happens that for low end 1S systems the Penryns are doing just fine against the Shanghais, for higher end 2S systems they used to be limited by memory bandwidth and AMD pulls ahead. No more is this the case, Intel now beats AMD in their own territory.
  • CHADBOGA - Tuesday, March 31, 2009 - link

    You probably also can't afford to buy a computer, so I doubt that Intel will be too concerned with your AMDZone insanity. LOL!!!!
  • smilingcrow - Tuesday, March 31, 2009 - link

    Those grapes you are chewing on sure sound sour to me. Try listening to a few tracks by The Fun Loving Criminals to help take away the bad taste.
  • cjcoats - Tuesday, March 31, 2009 - link

    There's more to HPC applications than you indicate: environmental modeling apps, particularly, tend to be dominated by memory access patterns rather than by I/O or pure computation. Give me a ring if you'd like some help with that -- I'm local for you, in fact...

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