Unigine slower with overclock, but 3Dmark is faster

[william p]

I've overclocked my Dell Dimension E520 QX6800 from 2.93GHz. base to 3.72GHz, stable.
In 3Dmark my physics scores and overall scores improved as expected. But they are much worse in Unigine benchmarks with the overclock applied. I used Throttlestop 6.00 software overclock to unlock volts and multiplier on the LGA775 CPU (usual Dell locked BIOS). It makes no difference whether Unigine starts with the O/C applied already, or if I apply it after opening the program. I lose 6-10 FPS in Heaven , and Valley. Does anyone have any insight into what might be causing this, and would any games be effected?

 

[blazorthon]

Did you overclock the FSB at all? This effects the memory performance and if the RAM might not be synchronized in frequency with the FSB and CPU. This isn't important for modern computers, but some old configurations that still had an on-board memory controller such as the LGA 775 systems can be heavily affected by this.

 

[william p]

No fsb and memory are @ 266 standard settings.

 

[unclewebb]

I remember hearing about this problem. I think changing the multiplier in Windows screws up the accuracy of one of the internal timers. When this happens, some programs will not be able to correctly calculate FPS. Overclocking can lead to lower benchmark scores because of this bug.

Does the built in TS Bench show your CPU running faster when it is overclocked? If yes then it truly is running faster.

 

[william p]

I found a workaround for this. But yes TS Bench is faster with O/C. When I reboot I lose the O/C and have to open TS and apply it in Windows. I did a restart and it was already there. I got a 15% improvement in Unigine Heaven- 115fps. I can check it with CPUZ, but if I open TS at all it slows back down again. I'm getting 50fps in Valley Extreme, and 59fps in Heaven Extreme, so I'm good now.10-15% increase from my 26% overclock.

I PM'd you with some numbers from my OCN account. But they're posted in threads at TPU, and OCN as Retrorockit.

 

[william p]

Using this workaround I got Passmark to accept my score. 2504, up from 2142 last time ( might have been GTX750 then). I think Passmark measured my fsb as 209 for a clock of 2.93 before with my O/C of 3.72 GHz.(14x266) applied. It would never accept my results before either. I suppose I've set the bar pretty high for Dell Dimension E520s there. So it's not the overclock itself.