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Memory bandwidth tests... any real differences (part 2)

Discussion in 'Overclocking & Cooling' started by graysky, May 10, 2008.

  1. graysky

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    About 7 months ago I posted data comparing two memory dividers (1:1 and 3:5 @ 333 MHz) on my then Q6600/P965 based system and concluded that for the 67 % increase in memory bandwidth, the marginal gains in actual performance weren't worth the extra voltage/heat.

    Since then I've upgraded my hardware to an X3360/P35 setup and wanted to revisit this issue. Again, two dividers were looked at: one pair running 8.5x333=2.83 GHz, and another running @ 8.5x400=3.40 GHz:

    333 MHz FSB:
    1:1 a.k.a. PC2-5300 (667 MHz)
    5:8 a.k.a. PC2-8500 (1,067 MHz)

    400 MHz FSB:
    1:1 a.k.a. PC2-6400 (800 MHz)
    4:5 a.k.a. PC2-8000 (1,000 MHz)

    I figured there would be a much greater difference in the 333 FSB case since the memory bandwidth increased by 60 % vs. 25 % in the 400 MHz FSB case. All other BIOS settings were held constant with the exception of the divider (and the strap) and the given FSB. Subtimings were set to auto and as such could vary as managed by the board which I found out, was required since manually settings some of the subtimings lead to either an incomplete POST, or an unstable system.

    The benchmarks were broken down into three categories:
    1) "Real-World" Applications
    2) 3D Games
    3) Synthetic Benchmarks

    The following "real-world" apps were chosen: x264, winrar, and the trial version of Photohop CS3. All were run on a freshly installed version of Windows XP Pro x64 SP2 w/ all relevant hotfixes. The 3D games were just Doom3 (an older game) and Crysis (a newer game). Finally, I threw in some synthetic benchmarks consisting of the Winrar self test, Super Pi-mod, and Everest's synthetic memory benchmark. Here is an explanation of the specifics:

    Trial of Photoshop CS3 – The batch function in PSCS3 v10.0.1 was used process a total of fifty-six, 10.1 MP jpeg files (226 MB totally):

    1) bicubic resize 10.1 MP to 2.2 MP (3872x2592 --> 1800x1200) which is the perfect size for a 4x6 print @ 300 dpi.
    2) smart sharpen (120 %, 0.9 px radius, more accurate, lens blur setting)
    3) auto levels
    4) saved the resulting files as a quality 10 jpg.

    Benchmark results are an average of two runs timed with a stopwatch.

    RAR version 3.71 – rar.exe ran my standard backup batch file which generated about 955 MB of rars containing 5,210 files totally. Here is the commandline used:
    Code:
    rar a -m3 -md4096 -v100m -rv40p -msjpg;mp3;tif;avi;zip;rar;gpg;jpg "f:\Backups\Backup.rar" @list.txt
    where list.txt a list of all the target files/dirs included in back up set. Benchmark results are an average of two runs timed with a stopwatch.

    x264 Benchmark HD – Automatically runs a 2-pass encode on the same 720p MPEG-2 (1280x720 DVD source) file four times totally. It contains two versions of x264.exe and runs it on both. The benchmark is the best three of four runs (FPS) converted to total encode time.

    Shameless promotion --> you can read more about the x264 Benchmark HD at this URL which contains results for hundreds of systems. You can also download the benchmark and test your own machine.

    3D Games Based Benchmarks

    Doom3 - Ran timeddemo demo1 a total of three times and averaged the fps as the result. Settings were 1,280x1,024, ultra quality with 8x AA.

    Crysis - Ran the included "Benchmark_CPU.bat" and "Benchmark_GPU.bat" both of which runs the pre-defined timedemo, looped four times. I took the best three of four (average FPS) and averaged them together as the benchmark. Settings were 1,024x768, very high for all (used the DX9 very high settings hack, and 2x AA.

    "Synthetic" Application Based Tests

    WinRAR version 3.71 – If you hit alt-B in WinRAR, it'll run a synthetic benchmark. This was run twice (stopped after 150 MB) and is the average of four runs.

    SuperPI / mod1.5 XS – The 16M test was run twice, and the average of the two are the benchmark.

    Everest v4.50.1330 Memory Benchmark - Ran this benchmark a total of three times and averaged the results.

    Hardware specs:
    Code:
    D.F.I. LP LT P35-TR2 (BIOS: LP35D317)
    Intel X3360 @ 8.5x400=3.40 GHz
    Corsair Dominator DDR2-1066 (TWIN2X4096-8500C5DF)
       2x 2Gb @ 5-5-5-15 (all subtimings on auto)
    
     (tRD=8) @ 667 MHz (1:1) @ 2.100V
     (tRD=7) @ 1,066 MHz (5:8) @ 2.100V
     (tRD=8) @ 800 MHz (1:1) @ 2.100V
     (tRD=6) @ 1,000 MHz (4:5) @ 2.100V
    
    EVGA Geforce 8800GTS (G92) w/ 512 meg
    Core=770 MHz
    Shader=1,923 MHz
    Memory=2,000 MHz
    Note: the performance levels (tRD) are set automatically by the board which wouldn't POST if I manually tweaked them. Even though they're different, I still feel the data are valid since this is the only way I can run them. In other words, if I'm going to run the higher dividers, it'll be as such or it won't POST!

    Without further ado, here are the data starting first with a 333 MHz FSB comparing the 1:1 vs. 5:8 divider (DDR2-667 vs. DDR-1066):
    [​IMG]

    Here are the averaged data visualized graphically:
    [​IMG]

    Now on to the 400 MHz FSB comparing the 1:1 vs. 4:5 divider (DDR2-800 vs. DDR2-1000):
    [​IMG]

    And graphically:
    [​IMG]

    As you can see, there way nothing spectacular in either the real-world category, or the 3D games category in comparison to the massive increase in memory bandwidth (shown on the graphs in red). In fact, I was surprised to see that there were really no gains by Doom3 and minimal gains by Crysis. This is probably due to the fact that the video card shoulders the burden of these games with Doom3 being the light-weight of the two. As expected, the synthetic benchmarks did pick-up on the larger bandwidth, but only in the case of the 400 MHz FSB did I see anything approaching the theoretical increase (14 % of 25 % vs 15 % of 60 %).

    If you read my first memory bandwidth post, perhaps the same conclusions can be drawn from these new data. One thing I'll add is that this new MB doesn't require extra voltage like my older P5B-Deluxe did to run the higher dividers, so it's not producing that much more heat. That said, I'm actually running the system with the 4:5 divider, since things seem to feel faster to me (windows opening, responsiveness, etc.) which are all unfortunately intangibles I can't measure.
    Last edited: May 11, 2008
    Kei, oli_ramsay, D4S4 and 3 others say thanks.
  2. trog100 New Member

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    i have never bothered tweaking memory over much cos its never shown me any noticeable real life gains.. only in memory bandwidth benches.. he he

    having said that neither has tweaking my cpu only in cpu benches.. he he he he

    trog
  3. erocker

    erocker Super Moderator Staff Member

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    Well done!:toast: Makes me feel better for running a lower FSB.
  4. jonmcc33

    jonmcc33 New Member

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    Yeah, similar to video card overclocking to be honest. People that overclock get XXX number of points more in 3DMark but real world the difference is not even noticeable. I flashed the BIOS of my X1900XT to an X1900XTX and noticed nothing faster at all, and some games started suffering from graphics tearing. I flashed back to the X1900XT and games were the same but no graphics tearing.
  5. NinkobEi

    NinkobEi

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    hmm, thats a very interesting read. it seems that game arent very memory dependent then. I guess we have a long ways to go before RAM is a bottleneck to a CPU.

    What you're saying is that its pointless to buy high quality ram because it makes little difference? ddr667=ddr1066? doesnt seem right to me, but then you have the tests to prove it..unless I am reading wrong.
  6. CrackerJack

    CrackerJack

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    well not many games uses more than 2gb. Hopefully in the near future we will see more x64 base games. CS3 is one of the heaviest programs, but it more cpu then memory. But till CS4 comes out. It should balance out awhole lot more. With my specs, during any encode. I'll use 100% cpu and only 35% of memory. :ohwell:
  7. jonmcc33

    jonmcc33 New Member

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    Memory bandwidth dependent, no. Nothing really is. Heck, you can run your FSB higher than your memory clock and still not suffer in performance.
  8. HTC

    HTC

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    Since pretty much no applications use 2 GBs of memory, why not test this wile multitasking? Say ... 3 or 4 programs @ the same time to maximize memory usage, and the compare. Dunno if it would work, though.

    Regarding higher speed memory, the only reason i can think of is the performance level (tRD) you can achieve with it:

    http://www.anandtech.com/mb/showdoc.aspx?i=3208&p=1

    Notice the gains in 3D06 by changing the tRD only! With lower speed memory, you can't get a low tRD, but you can with high speed memory.

    EDIT

    It's probably a good idea to include the RAM timings: 5-5-5-15 and 4-4-4-12 should have differences:

    [​IMG]

    Couldn't get any lower then 5-5-5-15 with this RAM ratio

    [​IMG]

    With this ratio, i was able to get 4-4-4-10.

    Notice the little difference in latency and the memory read, and the very big difference on both caches.

    Still, it all depends on the timings used for the original tests, IMO.
    Last edited: May 11, 2008
  9. trog100 New Member

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    i dont think any games use anywhere near 2 gigs of memory.. i loaded six high end-ish games all at once before i got to over 3 gig memory usage in task manager just to see.. i am useing XP thow..

    trog
  10. sneekypeet

    sneekypeet Unpaid Babysitter Staff Member

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    @ greysky...I got a few questions...

    #1 whos info is this, as the test specs dont match your own.

    #2 so you are telling me if I run my 667 ram at 1150MHZ, I will see no difference?

    #3 If this is infact your info, did you run the corsair in test with the same (way to friggin loose) subtimings.

    Realistically your subtiming skills put a huge dent in the rams performance even from stock levels.
    infrared says thanks.
  11. infrared New Member

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    Fairly interesting, but you havn't mensioned subtimings or voltage anywhere.

    IMO Overclocking is a compromise. It's not a choice between either stock or overclocked. Also, 1066mhz shouldn't require a lot of voltage, your ram should run @ 1066mhz with only 1.9-2.0v 5-5-5-12-[2-30-3-2-2] which would yeild good performance without getting too hot.
  12. graysky

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    #1 - it's mine from my system. I don't understand.
    #2 - I don't understand your question.
    #3 - I modified the post to answer your question as well as went from 5:6 (old post) to 4:5 (new post).
  13. sneekypeet

    sneekypeet Unpaid Babysitter Staff Member

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    #1 your system spec's<<<<<< dont come close to the testing equiptment.

    #2 you are saying in very simplified terms that there arent gains worth enough to OC my ram. So with my set of 667MHz ram running at 1150MHz I will see no real world performance gains?

    #3 by leaving all subtimings on auto then?
  14. graysky

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    I edited the first post switching the highest 400 MHz FSB run from 5:6 to 4:5 (960 MHz vs. 1,000 MHz) and included some info about subtimings to make things more clear.
    sneekypeet says thanks.
  15. HTC

    HTC

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    In my case, i went the other way around:

    I've lowered from 1062 to 884 and it's faster, @ least in Nero Recode it is.

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