CPU OC causes poor GFX performance?

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vexeus

Limp Gawd
Joined
Feb 7, 2006
Messages
495
I have a straaaange problem. First of all, I have an 8800GTS 640MB that is NOT OC'd. Periodically, my GFX run very poorly. To give you an idea, I get ~20 FPS in the beginning scene of 3dMark06, and it doesn't JUST effect 3dMark06... it happens in games as well. When the GFX run correctly, I get ~52 FPS in the beginning scene.

Here's how it works: I turn the computer on, I get crappy performance. I restart, I get crappy performance, I restart again, I finally get good performance (night and day difference here). Sometimes I have to restart several times. It seems VERY random and I'm not changing anything between restarts. Now once it runs well, it runs well until the computer restarts or turns off, then I have to go through the restart sequence until I get a "good" restart.

I'm nearly 100% positive that it is NOT a driver issue. I've reformatted 3 seperate times and installed 3 different drivers each time to no avail.

That leaves it down to one of two things: the graphics card or the motherboard (P5B deluxe).

I've tried to change all sorts of graphic settings in my BIOS, updating the BIOS, locking the PCI express frequency, and messing with random other GFX settings in the BIOS. Finally I just went to the stock 266 FSB and started up from there.

Now my applications run fine. Absolutely no hitches with stock settings and I've been able to restart the computer without it running poorly after the restart.

So what I'd like to know is... WHY IS IT DOING THIS? I never expected my CPU OC to effect the graphics card in such a weird way. Is there any other possibility that I've missed that might be causing this? Maybe my GFX card is acting funky but I don't know how to test that other than plugging it into another computer, which I don't have.
 
ok, tell me how well are u cooling your overclocked cpu?
 
List your computer specs :mad:

For now, try setting your PCIe frequency to 102mhz or so... Try a few numbers between 100 and 105. This is a fairly well known issue with various P965 chipset boards.
 
leSLIe said:
ok, tell me how well are u cooling your overclocked cpu?
Click to expand...

It is cooled by water (DDC2 / Storm / Crappy Rad but it keeps it below 42C full load) at a voltage of 1.2V and is completely stable.

Computer specs:

e6300 (good chip, have booted into Windows at 4GHz but I run it at 2.8 @ 1.2V normally)
P5B Deluxe WiFi
2x1GB Mushkin Redline (rated for 1000MHz but only running 800MHz at the normal overclock)
XFX 8800GTS 640MB
Silverstone ST52F PSU

I've tried changing the PCIe frequency, but didn't do enough testing at different values. I'm gonna give a few different PCIe frequency adjustments some serious testing though so I'll check back in a bit.
 
Well, I adjusted it to 106 MHz and the first boot was good. I'll give it a go for a bit, restart a few times and see what happens. Thanks for the tip. :)
 
Actually, I can ;)

I can't get it to fail in Orthos. I reckon I just got a good chip.

Regardless, I tried bumping it up to 1.3V and 106 MHz PCIe... started up this morning and it was running poorly again.

Do you think adjustments between 101-105 MHz will make a difference?
 
Trust me and try these: 1) Turn off EIST in the BIOS, and 2) Turn off C1E in BIOS -OR- set your power management in XP to "Home/Office Desk".

It can happen where the CPU gets ahead of the GPU and starts to idle. The features I've mentioned detect this idle state and cut back the CPU voltage and frequency to save power. Then the GPU or game asks for more work and everything in the CPU has to reset itself for doing work (raising the voltage and frequency).

This is just my guess but give it a try. However, your CPU "may" run slightly hotter as a result.

Good Luck!
 
Both are currently disabled and the power management is set to home/office desk. :(

Anyone else have any ideas?
 
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