NX8800GT 512mb OC further overclocking??

[troopertroop]

Heey Guys! I am new here so hello to you all!!
I just bought a new PC:

MSI P6N nForce 650i SLI V2
Q6600 C2Q @ 3.0 GHz
TakeMS 2 GB DDR2 RAM PC6400
2 x MSI NX8800GT 512mb OC (660/1950)
450GB HD

I hit a problem, I am trying to overclock my GPU's to (695/1995)! The oc is good, ntunes shows the card's running at 695/1995 but at 3dmark06 the performance is exactly the same as before oc?!
Is this because of the CPU-bottleneck?
I tried to OC the cpu further, but results in unstable system...

 

[Anaxagoras1986]

First off- WELCOME TO THE FORUMS!!!!!




I don't think your CPU should not be a bottle neck as my dual core went up when I OC'd my 8800GT OC.

What utility are you using to overclock your card? Some of them have troubles applying the overvlock without restarts, etc. I use Rivatuner and it has worked flawlessly for me so far.

 

[DarkhovaOC]

Same for me Rivatuner applies my Overclock as soon as i set it and also has pretty accurate temp readings....

 

[benscoobert]

check your pcie speed, should be 16x
what is your3dmark score ?

 

[troopertroop]

First of all, thanks a lot for the responses! Really appreciate it!

Well, I used nTuner first and now use Rivatuner! OC'ed the cards to 695/1995 and only see very little performance gain (16400 to 16600 3dmark06). I have a nForce 650i mobo which only supports 8x PCI-e when using SLI mode, could that be the problem? I read in reviews that 8x PCI-e should not be a bottleneck, even when they tested it on 8800GTX sli setup!