Multiple Load Points

For AnandTech Database Benchmarks, we have always focused on "real world" Benchmarks. To achieve this, we have used real applications with loads such that CPU utilization was 80-90%. Recently we discussed how most Enterprise Database Servers do not average 80-90% CPU utilization, but rather something closer to the 30-60% range. We thought it would make more sense to show performance where it is most likely going to be used, as well as the saturation numbers for the situations where the CPU is maxed. We feel this is consistent with how GPUs are reviewed, and how you might test drive a car. With GPUs, the cards are tested with varying resolutions, and anti-aliasing levels. With a car, you don't just hit the highway and see what the top end is.

We settled on six load points for testing. These load points are consistent across all platforms and are throttled from the client, independent of the platform being measured. We chose these load points as they split the load range into 6 roughly equal parts and allow us to extrapolate data between the points. The last/highest load point is a "saturation plus" load point to verify that we tested up the capability of the CPUs.

For any given load point, there is a defined number of threads. Each test is 20 minutes in duration, which includes an 8 minute warm up period followed by a 12 minute measured period. For a given load point, the client submits requests to the DB server as fast as the DB server will respond. The rate which the client is able to submit requests is measured during the final 12 minutes of the test and averaged to determine the Orders/Minute for Dell and Transactions/Minute for Forums. After much blood, sweat, and almost tears we were able to produce repeatable loads with an average deviation of 1.6%.

For each platform we ran the test 5 times for each load point and then averaged the 5 results. This was repeated for all loads, all tests, on all platforms... that is 300 test executions!!! (We won't even get into the debugging issues we had to deal with prior to the final results.) Thankfully, we managed to automate the process as much as possible when implementing the throttling mechanism for the load points.

The new benchmark suite Dell DVD Store Results
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  • Kiijibari - Thursday, July 13, 2006 - link

    quote:

    Performance scaling is not linear. I'm not sure how you can determine Opteron 3.0 performance by looking at only 2.4 and 2.6.


    Due to the integrated memory controller, the scaling of Opterons is "nearly" linear. 10% more frequency gives you around 8% better benchmark results. That is true for SMP setups, too. Because you also add more memory bandwidth channels with each CPU. Of course you have to setup NUMA correctly then (SRAT enable, NODE interleave disable). By using SRAT it may be possible to raise also the performance of a 2way system. I am not sure if it was done for the benched article, it just stated, that NUMA was "enabled" not which kind ... :(

    Anyways, I doubt that there will be a 3 GHz S940 Opteron. It will be S1207, i.e. it will feature DDR2 memory. Hence the performance scaling will be even better than "linear" (if you are willing to compare S940 vs. S1207) ;-)

    cheers

    Kiijibari
  • Accord99 - Thursday, July 13, 2006 - link

    quote:

    Due to the integrated memory controller, the scaling of Opterons is "nearly" linear. 10% more frequency gives you around 8% better benchmark results.

    Maybe if your benchmark is heavily CPU bound, but not every test is, especially ones dealing with multi-gigabyte databases where the storage subsystem becomes more important.

    Too bad there weren't more Opteron scores but a simple linear extrapolation from the two Opteron results would indicate that it would take a 3.4GHz Opteron to match the Woodcrest at saturation for the Dell Dvd Store benchmark, while a 3GHz Opteron would match the Woodcrest on the Forum benchmark at saturation. At the lower load points, it would probably take 4+GHz.
  • Kiijibari - Thursday, July 13, 2006 - link

    quote:

    Maybe if your benchmark is heavily CPU bound, but not every test is, especially ones dealing with multi-gigabyte databases where the storage subsystem becomes more important.

    Too bad there weren't more Opteron scores but a simple linear extrapolation from the two Opteron results would indicate that it would take a 3.4GHz Opteron to match the Woodcrest at saturation for the Dell Dvd Store benchmark, while a 3GHz Opteron would match the Woodcrest on the Forum benchmark at saturation. At the lower load points, it would probably take 4+GHz.


    Ah ok, sorry, if you were referring to Database test, of course I ment CPU bound applications.

    However i cant see your point. If you are looking on databases then the most important stuff is the I/O subsystem, if it does not stress the CPU too much. Thus I dont understand, why a Woodcrest should be better than an Opteron or a Netburst setup.
    As long as they feature the same harddisks & controllers and the CPU load is low, performance should be the same.

    But the 2 test here were all CPU bound. You can see that in the DVD test, all system ties until Load 3 or 4, after that the woodcrests pull off, due to its higher processing power.

    With the Forum benchmark, well I guess there were some problems with "throttling", mentioned in the text, thus the benchmark already benefits in stage 1 from the higher woocdrest performance.

    cheers

    Kiijibari
  • Kiijibari - Thursday, July 13, 2006 - link

    Yes indeed the test is (mostly) crap.

    On the one hand it is ok with me, because you can get (somehow) a woodcrest system and nothing better from AMD.

    However I expect something more in the conclusion then, but there is just that "we dont know" sentences: "How those parts will compete with future AMD products is unknown".

    Dear people at anandtech, I give you a hint concerning that topic:

    AMD will introduce 65nm technology. That will them enable to raise core clocks, while lowering power consumption. This is really no big speculation, it's a well known fact.

    In addition to that, there is also an error in the article, Socket F wont add FB-DIMM, it will add DDR2. Download & read the updated BIOS guide from the AMD webpage. (For your convenience, here is the link: http://www.amd.com/us-en/assets/content_type/white...">http://www.amd.com/us-en/assets/content...e/white_... )

    *No* I repeat *no* mention about FB-DIMM, but of course a lot information about DDR2.

    Hence you can easily draw the conclusion, that AMD will have the better wattage package in 2007, as they lower CPU wattage with 65nm, and lower RAM wattage with DDR2, too.

    Maybe the lowered DDR2 wattage will be already enough to even the Wodcrest wattage advantange with a Socket F 90nm CPU, but that is speculation. I dont know the absolut wattage differences between DDR1 and DDR2.

    Anyways, the current Intel advantage is just due to the former "mobile" CPU Core2. Everybody knows that Netburst was/is a power hungry monster and that FBDs draw more power than any other kind of memory nowadays. Thus, any wattage advantage is due to the CPU.

    cheers

    Kiijibari
  • defter - Thursday, July 13, 2006 - link

    quote:

    AMD will introduce 65nm technology. That will them enable to raise core clocks, while lowering power consumption. This is really no big speculation, it's a well known fact.


    Just a few months ago, when there were Conroe samples and benchmarks available some people were saying: "we know nothing about real performance let's wait for final benchmarks". Now when talking about 65nm Opterons these people are saying: "it's a fact that 65nm Opteron will be much faster" even though that there even aren't any samples available. Funny how things change...

    How about some real facts:
    - Fastest 130nm K8 reached 2.6GHz
    - First 90nm K8s became available in about October 2004
    - First faster-than-130nm 90nm K8 (2.8GHz model) became available in June 2005

    With 130nm->90nm transition it took AMD 9 months until the newer process (90nm) achieved higher clockspeeds than the older process (130nm). Now, you seem to think that this kind of situation is impossible with 65nm and K8 will get sudden and major boost immideately?


    quote:

    Maybe the lowered DDR2 wattage will be already enough to even the Wodcrest wattage advantange with a Socket F 90nm CPU, but that is speculation. I dont know the absolut wattage differences between DDR1 and DDR2.


    Well, the last part is pretty obvious. DDR2 consumes significantly less power with equal bandwidth than DDR1. However, I would guess that AMD fans would scream a bloody murder if somebody would benchmark Socket F Opteron with DDR2-400 :) When comparing DDR1-400 against DDR2-667, I doubt that there will be a significant difference in power consumption.
  • Kiijibari - Thursday, July 13, 2006 - link

    Hi,

    you cant compare it to Conroe, Conroe is a new architecture, first 65nm AMD chips will be a simple Die shrink, nothing to worry about as long AMD does not have major problems.

    I havent checked your introduction dates, but I remind something like the same. AMD always introduces mid-range CPUs first. Because of that, I did not state, that a 3 GHz part will be out around christmas (this year). it will be some time in 2007, maybe they will skip higher clock parts and move to lower clock QuadCore parts. I dont know. However Intel will have a clock advantage until then: It could also be, that they hold that advantage. But there is to much speculation with that, AMD is using SOI and adding SiGe with 65nm, Intel is not.

    To the RAM power consumption issue:

    FB-DIMMs also run with DDR2 memory chips, too. Thus the additional +5W FBD wattage(Source: http://www.techreport.com/etc/2006q2/woodcrest/ind...">http://www.techreport.com/etc/2006q2/woodcrest/ind... ) is (only) due to the controller.

    I dont think that there is a big wattage difference on different DDR2 speed grades, well there is surely some, but imporantant thing is the voltage, and that is always lower with DDR2 than DDR1 (1.8V vs. 2.5V).

    Concerning that topic:
    http://download.micron.com/pdf/pubs/designline/dl1...">http://download.micron.com/pdf/pubs/designline/dl1...

    There they calcualte 2.7W for moderate use of a DDR2-533 module and 3W for a DDR2-400 module under high load.
    Compared to DDR1 that is a 40-50% less power usage.(http://www.kingston.com/press/2006/memory/05b.asp)">http://www.kingston.com/press/2006/memory/05b.asp)

    Anyways FBD adds +5W with every other memory module. That's bad, cause normally you have a lot of them in servers :(

    But hopefully that will be changed with new, better controllers and/or bigger modules.

    cheers

    Kiijibari
  • JarredWalton - Thursday, July 13, 2006 - link

    Could be wrong (replying to Kiijibari), but DDR2 is pin compatible with FB-DIMMs; you just need to implement the corrected memory controller. Initial Socket F should be registered DDR2, but the rumor mill has that later revisions will include FB-DIMM support.
  • Kiijibari - Thursday, July 13, 2006 - link

    Sorry, didnt saw your post soon enough, otherwise I would have answered it in my other post :)

    FBD is *not* pin compatible to DDR2 modules, they have their own interface. But they use normal, off the shelf DDR2 chips, the same which are also used with DDR2 modules.
    Advantage of this is, that you can change the used memory modules, and the mainboard is still compatible to the new modules. That is due to the fact, that the systems just sees the FBD module controller, what is behind that, is not of interest.

    Because of this, there will be compatible DDR3 FBDs for current Bensley platforms.

    But there is also rumour that DDR3 modules will be compatible to DDR2 ones, too. There is very little difference(only voltage and 8xprefetch) between DDR2 and DDR3 and the modules will feature the same 240 pin interface.

    Anyways AMD will go to FBD later (~2008), maybe after the wattage problem has been solved by Intel et al ;-) ( source: http://pc.watch.impress.co.jp/docs/2006/0623/kaiga...">http://pc.watch.impress.co.jp/docs/2006/0623/kaiga... )

    But as I said earlier, Socket F is DDR2 only, no FBD in the BIOS guide.

    cheers

    Kiijibari
  • JarredWalton - Thursday, July 13, 2006 - link

    Er, sorry, but by "pin compatible" I mean it also uses 240 pins. Same size DIMMs, but you need the right type of memory controller - just like registered vs. unbuffered RAM. One way or another, I'm sure AMD will support FBD in the future; the question is when? Although, since they link RAM to each CPU socket it's certainly not as big of a concern since two sockets already support four memory channels. If they can get 4 registered DIMMs per channel, they're already up to 16 DIMM sockets.

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