I read around that overclocking the PCIe to 120mhz brings more overclocking potential to vidcards, thus improving the frames. I also read that overclocking it too high will cause data corruption for SATA drives.

Is it safe to overclock the PCIe frequency? Will I be able to overclock my video card much more than 680/1000? MSI site states anything above 120mhz isn't recommended...

I would lock the PCIe frequency to 100mhz. Anything higher can cost instabilities, and I dont believe it would help performance on stock levels or help to achieve higher OC's. I could be wrong, but from experience and what I have read it seems to me that locking it at 100mhz is in most cases going to be your optimal setting. Hope this helps.

Best,

3Ball

Thanks for the reply. I know going to high will cause instabilities, but I believe it does increase the frame rates. I just tried it at 120mhz and instead of the usual ~12800 for 3dmark 06, I got a score closer to ~12900. But if it does cause instabilities, probably it's not worth it. However I also read somewhere that increasing it can improve stability.

Now I'm confused

I would run 3Dmark 4-5 times and take an average. Mine are always within +/- 3% of each other and that 12900 is within the 3% error rate.

Rigto. I did it around 5 times, each with a setting of higher than 100mhz. To me it seems as if the 120mhz is the optimal spot, since I get ~12900 consistently. Before, I get ~12800, 12817 being the highest I have gotten.

What graphics card?

In my sig, the 8800GTS 320mb

Haha my bad.

Anyways, have you tried OCing it at 100 MHz PCIe and then again at 120 MHz PCIe? I wouldn't mind seeing some results if you feel like being excessive OCD... I mean Benchmarking 3DMark06 10 times at all stock and getting a baseline. 10 times at OC'd with 100 MHz PCIe, 10 times at stock graphics 120 PCIe, and 10 times OC'd with 120 PCIe and comparing the differences in solid OC, 3DMark06, and if you got any improvement in OC ability.

Okay why not? Well truthfully 680mhz isn't stable, just purely for benchmarking. At 100mhz, 670mhz isn't stable either. However when I brought it to 120mhz, I could get to 675mhz without the 3dmark crashing every so often.

I'll update the results a little later.

Thanks man!

If you're like me I always try to do my own benchmarks. I did my own benches of 1333 MHz FSB vs 1600 MHz FSB and 1066 vs 1333 and so on.

I also try to do my own on memory bandwidth and timings. It's pretty telling to see it for yourself rather than rely on what some website says.

If you can, and/or have time for it try to through in some actual game benchmarks as well...maybe something like the source stress test or something? Just curious.

Best,

3Ball

It's a pretty interesting topic. I haven't seen much on this other than people saying lock it to 100 MHz.

Well in many OC'ing guides such as the one on these forums it is suggested to leave it locked at 100mhz.

http://www.tomshardware.com/forum/ [...] uals-guide

So that is one area where I have seen it, but the discussion came up alot more back when the C2D's and X2's were being learned to be OC'd.

Best,

3Ball

Too bad I don't have CS installed on my pc

Although I think 3dmark is sufficient when it comes to comparing overclocks, I'll run it through COD4 a couple of times. I'm about half done with my testing, and so far there is a slight increase in performance...

Okay finally done with the testings

Objective:
To find if increasing the PCIe frequency improves performance

Test bed:
Q6600 @ 3.15ghz
4x1gig ram @ 700mhz
Xfx 8800GTS 320mb XXX
GA-P35C-DS3R

Procedures:
Set PCIe to 100mhz. Set vidcard clock speeds to stock (580/1500/900). Run 3dmark06 5 times. Then overclock to 665/1618/1000 and restart pc. Run 3dmark 5 times. Repeat for 110mhz and 120mhz.

Results(using 3dmark06):
100mhz PCIe:

580/1500/900
Score:11623

665/1618/1000
Score:12746

110mhz PCIe:

580/1500/900
Score:11624

665/1618/1000
Score:12792

120mhz PCIe:

580/1500/900
Score:11636

665/1618/1000
Score:12807

Highest clock speed(core only)*:
100mhz:665mhz, Score-12746
110mhz:N/A
120mhz:675mhz, Score-12853

*Note this is done by COD4. I ran the whole SP COD4 with the overclocked settings. If it crashed, artifacted, or freezed, I lowered the core clock speeds. I did not want to overclock the Shader clock and memory clock any further.

Conclusion:
Setting the PCIe higher than 100mhz does increase performance slightly. If raising the PCIe does not cause instability, it may be worth it. I'm sure I could raise the memory clock higher, but I feel that 1000mhz is a bit high already.

Well that shows it Increasing the PCIe frequency increases performance slightly and improves overclocking. The temps never exceeded 70C.