Server Clash: DELL's Quad Opteron DELL R815 vs HP's DL380 G7 and SGI's Altix UV10
by Johan De Gelas on September 9, 2010 7:30 AM EST- Posted in
- IT Computing
- AMD
- Intel
- Xeon
- Opteron
Response Times
At low 30% to 60% utilization, we cannot compare throughput. The throughput is more or less the same on all machines. Response times make the difference here. It is important to interprete the numbers carefully though.
This might come as a surprise, but the dual Xeon X5670 inside the HP DL380 G7 comes out as the best (fastest) server here. The Xeon X5670 extracts more parallelism out of the code of one thread and clocks one core quite a bit higher than the other cores. Response times are measured per URL/query, thus single threaded performance is the determining factor until all cores are working as hard as they can.
We are working on about 30 virtual CPUs, or “worlds” in the eye of the ESX scheduler. The dual Xeon X5670 can offer 24 Hardware Execution Contexts (HECs), the quad Opteron 6174 can offer 48. However, the Opteron cannot leverage the HEC advantage enough in this scenario. The Xeon X7560 has more or less the same core, but a lower clock but it does not suffer from the small scheduling overhead that the Xeon 5670 suffers having less HECs than VMs running. So that is why the 2.26 Xeon 7560 offers only 10-15% higher response times.
So how important is this? Is the Xeon twice as fast as the Opteron? Not really. Remember that we measured this over low latency LAN. A typical web request send from Europe to the AnandTech server in North Carolina will take up to 400 ms. In that scenario the extra 100 ms difference between the Xeon and Opteron will start to fade.
The higher the load, the more the Opteron will narrow the gap as it starts to leverage the higher throughput.
The difference in user experience is hardly as dramatic as the numbers indicate. Whether you will care or not will also depend on the application. Some web requests can take up to 2 seconds (220 ms is only an average), so it really depends on how complex your application is. If you run at a light load and the heaviest requests are answered within half a second, nobody will notice if it is 300 or 180 ms. But if some of your requests take more than a second even under "normal" load, this difference will be noticeable.
So response time under "normal" load might not be as important as under heavy load, but the numbers above also show you that throughput is not everything. Single threaded performance is still important, and we definitely feel that the UltraSparc T2 approach is the wrong one for most business applications out there. A good balance between single-threaded and multi-core is still advisable for our web applications that get heavier as we build upon feature rich Content Management Systems.
Once we load the systems close their maximum, a totally different picture emerges. Below you can see the response times with much higher concurrencies and the four tiles of full vApus Mark II testing. Remember that the concurrencies are 10 times higher and the OLTP test is included.
The quad Xeon wins in the web tests while the quad Opteron leads in the OLAP tests. The OLAP test is more bandwidth sensitive and that is one of the reasons that the quad Opteron configurations excel there.
The dual Xeon 5670 has only 24 HECs to offer and 72 worlds are constantly demanding CPU power. No wonder that the dual Xeon is completely swamped and as a result has the worst response times.
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pablo906 - Saturday, September 11, 2010 - link
High performance Oracle environments are exactly what's being virtualized in the Server world yet it's one of your premier benchmarks./edit should read
High performance Oracle environments are exactly what's not being virtualized in the Server world yet it's one of your premier benchmarks.
JohanAnandtech - Monday, September 13, 2010 - link
"You run highly loaded Hypervisors. NOONE does this in the Enterprise space."I agree. Isn't that what I am saying on page 12:
"In the real world you do not run your virtualized servers at their maximum just to measure the potential performance. Neither do they run idle."
The only reason why we run with highly loaded hypervisors is to measure the peak throughput of the platform. Like VMmark. We know that is not realworld, and does not give you a complete picture. That is exactly the reason why there is a page 12 and 13 in this article. Did you miss those?
Per Hansson - Sunday, September 12, 2010 - link
Hi, please use a better camera for pictures of servers that costs thousands of dollarsIn full size the pictures look terrible, way too much grain
The camera you use is a prime example of how far marketing have managed to take these things
10MP on a sensor that is 1/2.3 " (6.16 x 4.62 mm, 0.28 cm²)
A used DSLR with a decent 50mm prime lens plus a tripod really does not cost that much for a site like this
I love server pron pictures :D
dodge776 - Friday, September 17, 2010 - link
I may be one of the many "silent" readers of your reviews Johan, but putting aside all the nasty or not-so-bright comments, I would like to commend you and the AT team for putting up such excellent reviews, and also for using industry-standard benchmarks like SAPS to measure throughput of the x86 servers.Great work and looking forward to more of these types of reviews!
lonnys - Monday, September 20, 2010 - link
Johan -You note for the R815:
Make sure you populate at least 32 DIMMs, as bandwidth takes a dive at lower DIMM counts.
Could you elaborate on this? We have a R815 with 16x2GB and not seeing the expected performance for our very CPU intensive app perhaps adding another 16x2GB might help
JohanAnandtech - Tuesday, September 21, 2010 - link
This comment you quoted was written in the summary of the quad Xeon box.16 DIMMs is enough for the R815 on the condition that you have one DIMM in each channel. Maybe you are placing the DIMMs wrongly? (Two DIMMs in one channel, zero DIMM in the other?)
anon1234 - Sunday, October 24, 2010 - link
I've been looking around for some results comparing maxed-out servers but I am not finding any.The Xeon 5600 platform clocks the memory down to 800MHz whenever 3 dimms per channel are used, and I believe in some/all cases the full 1066/1333MHz speed (depends on model) is only available when 1 dimm per channel is used. This could be huge compared with an AMD 6100 solution at 1333MHz all the time, or a Xeon 7560 system at 1066 all the time (although some vendors clock down to 978MHz with some systems - IBM HX5 for example). I don't know if this makes a real-world difference on typical virtualization workloads, but it's hard to say because the reviewers rarely try it.
It does make me wonder about your 15-dimm 5600 system, 3 dimms per channel @800MHz on one processor with 2 DPC @ full speed on the other. Would it have done even better with a balanced memory config?
I realize you're trying to compare like to like, but if you're going to present price/performance and power/performance ratios you might want to consider how these numbers are affected if I have to use slower 16GB dimms to get the memory density I want, or if I have to buy 2x as many VMware licenses or Windows Datacenter processor licenses because I've purchased 2x as many 5600-series machines.
nightowl - Tuesday, March 29, 2011 - link
The previous post is correct in that the Xeon 5600 memory configuration is flawed. You are running the processor in a degraded state 1 due to the unbalanced memory configuration as well as the differing memory speeds.The Xeon 5600 processors can run at 1333MHz (with the correct DIMMs) with up to 4 ranks per channel. Going above this results in the memory speed clocking down to 800MHz which does result in a performance drop to the applications being run.
markabs - Friday, June 8, 2012 - link
Hi there,I know this is an old post but I'm looking at putting 4 SSDs in a Dell poweredge and had a question for you.
What raid card did you use with the above setup?
Currently a new Dell poweredge R510 comes with a PERC H700 raid card with 1GB cache and this is connect to a hot swap chassis. Dell want £1500 per SSD (crazy!) so I'm looking to buy 4 intel 520s and setup them up in raid 10.
I just wanted to know what raid card you used and if you had a trouble with it and what raid setup you used?
many thanks.
Mark
ian182 - Thursday, June 28, 2012 - link
I recently bought a G7 from www.itinstock.com and if I am honest it is perfect for my needs, i don't see the point in the higher end ones when it just works out a lot cheaper to buy the parts you need and add them to the G7.