I posted this on extremeoverclocking first but am getting no responses so decided I would post it here also, it is divided into the 3 posts I made there.


I just O'cd my Q6600 up to 3g once again and when I rebooted my keyboard quit working, figure this out if you can. I went back into bios and reset to default and now it works again, I am using a Merc Stealth and razor mouse. At first boot after Oc keyboard worked to inter password but didn't when vista finished loading, 2nd boot wouldn't work at enter password stage so turnd off PC then rebooted to default. Should mention that nvidia drivers quit and recovered at 1st boot.


PCI-E was at 100 and couldn't find a PCI setting anywhere with anything close to 33. wierd as it seems when I set bios back to default everything is fine but if I change anything including setting ram to specs my keyboard just quits, it does work while in bios but quits during windows loading. I am going back and trying everything 1 step at a time and see if I can find where it is quiting at will gwet back to you.

After reset, ram goes back to DDR2 800 and when I reset it to specs of 1066 and 5-6-6-18 with no CPU Oc that is when keyboard quits, nothing else is changed. I don't know what happened as ram was running fine at 1066 before I tried O'cing CPU and I did not do anything to ram settings.

Okay this is really getting wierd, I linked my cpu and ram and tried again. Now when I boot, the keyboard is working again but I was no longer conected to my network. I had to once again reset to default bios setting and reboot to get my network back. Things just keep getting better.

More system specs please, especially motherboard.

You need to make sure that PCI bus is locked at 33. Also, try (at your own risk) giving the CPU more voltage.

I looked for PCI bus setting but couldn't find it in the bios. left cpu v on auto and it was showing as 1.385v or real close to that. I have had it O'ced up to 3.2 before with no mProblems so I am at a loss as to why I am having these issues now.

XFX 780i 3 way sli MB
PC power and cooling 860w PSU
8 gig OCZ DDR2 1066 ram
2) MSI n9800GT in SLI
Windows Vista home premium 64bit
antec 800 case
core 2 quad Q6600
Thermalright Ultra 120 Extreme CPU cooler

Nice power supply.

Ok, I really think that bumping the voltage to 1.4 or 1.41 volts (or maybe even higher) might help you out here. Most of the time, overclocking your CPU by any useful amount requires a voltage bump to maintain stability at higher clock speeds. Just try bumping it up a bit and see if that fixes your problem. Increase voltage at your own risk however, as increasing it too far can and will fry the CPU.

I went back into my bios and the only thing I could find was in PnP/PCI configuration "PCI latency Timer (CLK)" and it was at 32, is this what you were asking about? I will try buimping the CPU v, thanks for the reply.

There should be something along the lines of a PCI bus speed clock, and it should be set at 33.33 MHz. It should be located with the other overclocking options. If it's not there, it is either automatically locked at 33.33 MHz, or your board does not have the option of locking it.

I believe the PCI Latency Timer is something unrelated.

I checked everything in the advanced settings for O'cing and couldn't find anything with a setting like 33.33MHz so I am assuming it isn't availible in these bios.

I have set my CPU to 3GHz, ram was running at 800 so I started bumping it 100 at a time and it is now at 1066 where it should be with no apparent issues so I will stress test and see if it keeps working or not keep fingers crossed.

if u read u're mb manual there should be a setting to lock pci bus before u ever start overclocking.

nickc I read my MB manual and there is no setting in these bios or this MB to lock PCI bus but using cpu-z it shows PCI bus at 33.33mhz

well that is what it is running at then, and that is where it should be...