Power Extremes: Idle and Full Load

Now that we have real OEM servers in the lab for all platforms, we can finally perform a decent power consumption comparison. All servers have 64GB and the disk configuration is also exactly the same (four SSDs). In the first test we report the power consumption running vApus Mark II, which means that the servers are working at 95-99% CPU load. Please note that although the CPU load is high, we are not measuring maximum power: you can attain higher power consumption numbers by using a floating point intensive benchmark such as Linpack. But for virtualized—mostly integer—workloads, this should be more or less the maximum power draw.

We test with redundant power supplies working. So the Dell R815 uses 1+1 1100W PSUs, the SQI Altix UV10 uses 2+2 850W PSU and the HP uses the 1+1 460W PSUs.

vApus Mark II—VMware ESX 4.1—full load

You might think that the four 850 W PSU (2+2) are a serious disadvantage for the SGI server, but they are an advantage. The DELL and HP servers split their load over the two PSUs, resulting in somewhat lower efficiency, while the redundant PSUs of the SGI server consume exactly … 0 Watt. The power distribution board of the SGI Altix UV 10 /QSSC-4R has a very “cool” feature called “cold redundancy”. Although the redundancy is fully functional, the 2 redundant PSUs do not consume anything until you pull the active PSUs out.

The Dell R815 consumes less than two HP DL380 G7s, so the performance/watt ratio is competitive with the dual Xeon platform and without any doubt superior to the quad Xeon platform. If you compare the R815 with two Opterons with the HP DL380, you will notice that the R815 server is very efficient . The dual Opteron is hardly consuming more than the HP dual Xeon server while it has an 1100W PSU (not ideal when you are consuming only 360W) and contains of course a slightly more complex quad socket board. The quad socket R815 server is thus very efficient as the difference with a dual socket Xeon server is minimal.

Comparing the dual with the quad Opteron 6174 power numbers, we notice a relatively high increase in power: 244 Watt. So for each Opteron that we add, we measure 122 W at the wall. This 122 W includes a few Watts of PSU losses, VRM and DIMM wiring losses. So the real power consumed by the processor is probably somewhere between 100 and 110W. Which is much closer to the TDP (115W) than the ACP (80W) of this CPU.

Idle power measurements are hardly relevant for consolidated virtualized environments but they are a very interesting point of reference.

 vApus Mark II—VMware ESX 4.1—idle Power 

As you can see, it is not only the 130W TDP Xeon 7560 that make the SGI Altix UV10/QSSR-4R consume so much. We measure 372W difference between idle and full load, which is about 93W per CPU. That is not a huge difference if you consider that the difference is 350W for the four Opterons, and 170W for the two Xeons 5670. The Xeon 7500 CPU is capable of power gating the cores and will not consume much in idle. So we may say that the difference is not made by the CPUs: all CPU will consume in the range of 90-110W.

The problem is the complexity of the server. The QSSC-4R/ SGI Altix UV 10 pays a price for its scalability and serviceability: the memory riser boards alone consume almost 20W per board. So eight memory boards can add up to 160W. Being able to power 11 PCIe cards means that your power budget grows even more as the complexity of the I/O board is higher and the engineers have to size the power supply for the use of many more I/O cards and memory. The result is that the performance ratio of the quad Xeon 7500 is rather mediocre: you need three times the power of an HP DL 380 G7 and you only get twice the performance. At idle, it is even worse.

The Opteron 6174 needs a bit more power than its 80W ACP tag promises, but the performance/Watt ratio is very good, on par with the HP DL 380 G7. You need almost two HP DL380 G7 to achieve the same performance, but the DELL R815 needs 10% less power than two HP DL380 G7. So the DELL R815 is definitely a match for two DL380 G7s in the performance/watt category. And it beats two HP DL380 G7 with a healthy margin in other departments: CAPEX ($14000 with 128GB versus 2 x $9000 with 64GB), OPEX costs (only one machine to set up and manage), and rack space (2U vs 4U).

But… maximum power and minimum power are not very realistic. How about a real world scenario?

vApus Mark II Real World Power
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  • cgaspar - Friday, September 10, 2010 - link

    The word you're looking for is "authentication". Is a simple spell check so much to ask?
  • JohanAnandtech - Friday, September 10, 2010 - link

    Fixed.
  • ESetter - Friday, September 10, 2010 - link

    Great article. I suggest to include some HPC benchmarks other than STREAM. For instance, DGEMM performance would be interesting (using MKL and ACML for Intel and AMD platforms).
  • mattshwink - Friday, September 10, 2010 - link

    One thing I would like to point out is that most of the customers I work with use VMWare in an enterprise scenario. Failover/HA is usually a large issue. As such we usually create (or at least recommend) VMWare clusters with 2 or 3 nodes. As such each node is limited to roughly 40% usage (memory/CPU) so that if a failure occurs there is minimal/0 service disruption. So we usually don't run highly loaded ESX hosts. So the 40% load numbers are the most interesting. Good article and lots to think about when deploying these systems....
  • lorribot - Friday, September 10, 2010 - link

    It would be nice to see some comparisons of blade systems in a similar vein to this article.

    Also you say that one system is better at say DBs whilst the the other is better at VMware, what about if you are running say a SQL database on a VMware platform? Which one would be best for that? How much does the application you are running in the VM affect the comparative performance figures you produce?
  • spinning rust - Saturday, September 11, 2010 - link

    is it really a question, anyone who has used both DRAC and ILO knows who wins. everyone at my current company has a tear come to their eyes when we remember ILO. over 4 years of supporting Proliants vs 1 year of Dell, i've had more hw problems with Dell. i've never before seen firmware brick a server, but they did it with a 2850, the answer, new motherboard. yay!
  • pablo906 - Saturday, September 11, 2010 - link

    This article should be renamed servers clash, finding alternatives to the Intel architecture. Yes it's slightly overpriced but it's extremely well put together. Only in the last few months has the 12c Opteron become an option. It's surprising you can build Dell 815's with four 71xx series and 10GB Nics for under a down payment on a house. This was not the case recently. It's a good article but it's clearly aimed to show that you can have great AMD alternatives for a bit more. The most interesting part of the article was how well AMD competed against a much more expensive 7500 series Xeon server. I enjoyed the article it was informative but the showdown style format was simply wrong for the content. Servers aren't commodity computers like desktops. They are aimed at a different type of user and I don't think that showdowns of vastly dissimilar hardware, from different price points and performance points, serve to inform IT Pros of anything they didn't already know. Spend more money for more power and spend it wisely......
  • echtogammut - Saturday, September 11, 2010 - link

    First off, I am glad that Anandtech is reviewing server systems, however I came away with more questions than answers after reading this article.

    First off, please test comparable systems. Your system specs were all over the board and there were way to many variables that can effect performance for any relevant data to be extracted from your tests.

    Second, HP, SGI and Dell will configure your system to spec... i.e. use 4GB dimms, drives, etcetera if you call them. However something that should be noted is that HP memory must be replaced with HP memory, something that is an important in making a purchase. HP, puts a "thermal sensor" on their dimms, that forces you to buy their overpriced memory (also the reason they will use 1GB dimms, unless you spec otherwise).

    Third, if this is going to be a comparison, between three manufactures offerings, compare those offerings. I came away feeling I should buy an IBM system (which wasn't even "reviewed")

    Lastly read the critiques others have written here, most a very valid.
  • JohanAnandtech - Monday, September 13, 2010 - link

    "First off, please test comparable systems."

    I can not agree with this. I have noticed too many times that sysadmins make the decision to go for a certain system too early, relying too much on past experiences. The choice for "quad socket rack" or "dual socket blade" should not be made because you are used to deal with these servers or because your partner pushes you in that direction.

    Just imagine that the quad Xeon 7500 would have done very well in the power department. Too many people would never consider them because they are not used to buy higher end systems. So they would populate a rack full of blades and lose the RAS, scalability and performance advantages.

    I am not saying that this gutfeeling is wrong most of the time, but I am advocating to keep an open mind. So the comparison of very different servers that can all do the job is definitely relevant.
  • pablo906 - Saturday, September 11, 2010 - link

    These VMWare benchmarks are worthless. I've been digesting this for a long long time and just had a light bulb moment when re-reading the review. You run highly loaded Hypervisors. NOONE does this in the Enterprise space. To make sure I'm not crazy I just called several other IT folks who work in large (read 500+ users minimum most in the thousands) and they all run at <50% load on each server to allow for failure. I personally run my servers at 60% load and prefer running more servers to distribute I/O than running less servers to consolidate heavily. With 3-5 servers I can really fine tune the storage subsystem to remove I/O bottlenecks from both the interface and disk subsystem. I understand that testing server hardware is difficult especially from a Virtualization standpoint, and I can't readily offer up better solutions to what you're trying to accomplish all I can say is that there need to be more hypervisors tested and some thought about workloads would go a long way. Testing a standard business on Windows setup would be informative. This would be an SQL Server, an Exchange Server, a Share Point server, two DC's, and 100 users. I think every server I've ever seen tested here is complete overkill for that workload but that's an extremely common workload. A remote environment such as TS or Citrix is another very common use of virtualization. The OS craps out long before hardware does when running many users concurrently in a remote environment. Spinning up many relatively weak VM's is perfect for this kind of workload. High performance Oracle environments are exactly what's being virtualized in the Server world yet it's one of your premier benchmarks. I've never seen a production high load Oracle environment that wasn't running on some kind of physical cluster with fancy storage. Just my 2 cents.

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