Investigations into Socket 939 Athlon 64 Overclocking
by Jarred Walton on October 3, 2005 4:35 PM EST- Posted in
- CPUs
Doom 3 Performance
More so than any other game that we tested, Doom 3 is going to be held up by the X800 Pro. With the engine being heavily optimized for NVIDIA's architecture - or simply being a better fit for OpenGL and shadows, if you prefer - performance scaling drops off rapidly with increasing resolutions. Whether future Doom 3 engine licensees will exhibit similar results is up for debate, Call of Duty and Wolfenstein: Enemy Territory, for example, don't correlate directly with Quake 3 performance. However, we expect NVIDIA to maintain some advantage over ATI in Quake 4 and Quake Wars.
At 640x480 without antialiasing, Doom 3 still manages to gain 43% more performance. That drops off quickly to 34% at 800x600 and 18% at 1024x768. Consider our 1024x768 4xAA results to be something of a reality check. It doesn't matter how fast your CPU is if your bottleneck is somewhere else. The 1% increase between 1.8 GHz and 2.7 GHz performance is testament to this fact. Higher quality RAM, once again, buys about 5% more performance relative to budget RAM, though the 2T timing at 9x300 is 12% slower than performance RAM. It's also slower than the value RAM at 9x289, which is a trend seen in BF2 and several other tests.
More so than any other game that we tested, Doom 3 is going to be held up by the X800 Pro. With the engine being heavily optimized for NVIDIA's architecture - or simply being a better fit for OpenGL and shadows, if you prefer - performance scaling drops off rapidly with increasing resolutions. Whether future Doom 3 engine licensees will exhibit similar results is up for debate, Call of Duty and Wolfenstein: Enemy Territory, for example, don't correlate directly with Quake 3 performance. However, we expect NVIDIA to maintain some advantage over ATI in Quake 4 and Quake Wars.
At 640x480 without antialiasing, Doom 3 still manages to gain 43% more performance. That drops off quickly to 34% at 800x600 and 18% at 1024x768. Consider our 1024x768 4xAA results to be something of a reality check. It doesn't matter how fast your CPU is if your bottleneck is somewhere else. The 1% increase between 1.8 GHz and 2.7 GHz performance is testament to this fact. Higher quality RAM, once again, buys about 5% more performance relative to budget RAM, though the 2T timing at 9x300 is 12% slower than performance RAM. It's also slower than the value RAM at 9x289, which is a trend seen in BF2 and several other tests.
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Furen - Monday, October 3, 2005 - link
Actually, Winchesters are pretty bad overclockers. They were even worse overclockers than newcastles and clawhammers back when they came out, which is why the FX-55 was clawhammer based rather than Winchester based.ksherman - Monday, October 3, 2005 - link
hmmm... Im running a 3000+ winchester, and ive got it to 2.56GHz... thats quite an over clock if you ask me... you would probably be the first person I have EVER say that the winchesters do not OC well...ksherman - Monday, October 3, 2005 - link
is there any performance hit when using memory dividers? I have heard that there is, as the memory and CPU are running on different frequencies... and is it better to keep you RAM @ DDR400, and use dividers or run the RAM @ DDR480?ShadowVlican - Monday, October 3, 2005 - link
so i'm guessing basically, A64's prefer low latency than high frequencyJarredWalton - Monday, October 3, 2005 - link
Pretty much. If you think about it, 10x240 with DDR333 setting is actually identical to 12x200 with DDR400 setting. The RAM is at DDR400 in either case. The difference between a 960 MHz HT speed and 1000 MHz HT speed is... well, if you measure more than a 1% difference, I'd be surprised. :)Wesley Fink - Monday, October 3, 2005 - link
Memory dividers DO make a difference in performance on the Intel platform, where the memory controller is in the chipset and latency is relatively high. Basically, the architecture derives memory ratios with added overhead which can definitely impact performance, and 1:1 memory ratio is best.However, the memory controller on the Athlon 64 is on the processor and memory frequencies are derived from HT on the A64, without adding overhead. That means, theoretically, memory dividers should have NO impact at all on Athlon 64 memory performance - everything else being equal (which it rarely is).
ksherman - Monday, October 3, 2005 - link
well i decided to go for the RAM dividers... upto 2.56GHz, memory using the 5/6 divider (DRAM/FSB) RAM @ DDR466 @ 2-2-2-7 3.3V! was at 2.13Ghz, since I didnt want to use memory dividers. so a nice jump in speed! now I just got to find do some benchies! BTW- I am using a DFI Ultra-D and it is the greatest board I have ever owned! havent done the SLI mod yet, but I dont need toksherman - Monday, October 3, 2005 - link
hmm... guess if i read the WHOLE article... ;-)good article though! I highly reccomend the 'Value VX' RAM aka OCZ Value RAM, since when you put enough voltage into it (3.2V in my case) it overclocks like a charm! Im getting DDR 480 with tight timings (not EXATLY sure, but something 2-2-3-8 1T)
Garyclaus16 - Monday, October 3, 2005 - link
Well,...the article states that there have been performance hits with higher dividers. Best way to find out with yourself is to do your own benches! No two systems will overclock exactly the same, so the best way to figure something out is to try it on your own..Aquila76 - Monday, October 3, 2005 - link
If your RAM will run stably at DDR480, leave it. I had to drop mine down becase there's some issue with the mobo higher than 250MHz.