Q9450 EVGA 790i OC causes video stutter

I put together my computer with water cooling. The board is an EVGA 790i ultra, and a Q9450. The memory is OCZ SLI 2048MB PC16000 DDR3 2000MHz. I have two 780 video cards in SLI and I run the water through them. Stock everything runs very smoothly. I upped the voltage to 1.3 and the FSB to 1600, and I can run four prime95's for an hour with no problem (though the heat my large three fan radiator is giving off is impressive during the Prime test) At stock the video is smooth, but in Counterstrike Source when the computer is overclocked the video has artifacts and stutters. I reset everything to stock the video is smooth, and then when I set back to OC it stutters again. The video and CPU run no more than 50's during Prime, and much less normally. Could I be overclocking the video bus some how?

Be gentle, I'm an OC noob.

Have you increased the PCI-E clocks at all? .. Also, are you running your RAM unlinked with the FSB? Your CPU might need more then 1.3v to run at 3.2GHz or the motherboard's SPP might need more voltage .. There's lots of things which could be causing it .. But artifacting sounds more like a problem with the graphics cards, does your PC crash when you get artifacts??

thanks

I upped the voltage to 1.32 which and set the pci-e to 100. I have been playing counterstrike all night with no problems. I really get a kick out of running my chip at 3200 which is like intel's fastest chip.

Good to hear, your problems were likely stemming from the PCI-E bus speed .. At some point you need to have a proper go at overclocking - set it back to stock and work your FSB up in stages, stress testing until your get errors .. Then you bump up the voltage

thanks

I will do what you say. I will start at stock and test everything (PRIME, memtest). Then I will up the FSB to 1400, 1500, etc. until I get errors. I assume that if I can run overnight that I can consider the computer stable. When I hit the first error, I will start upping the CPU voltage. Here is where I get confused. I can not only up the CPU voltage, but others like the memory and FSB. If increasing the CPU voltage doesn't fix the problem, where would you start next?

Right now at stock voltages and 1600 FSB I can run PRIME for one to two hours before one of the cores has an error.

With the 790i boards you can unlink the RAM from the FSB (so you can overclock the CPU separate of your RAM), do this and set your RAM to the timings/speed/voltage it is rated for then basically forget about it .. When you start getting errors the first thing to up is the CPU vCore, at low FSBs (up to I'd say around 1500) leave the FSB voltage at Auto, after around 1500 you'll have to then try upping the SPP voltage and CPU FSB voltage. If you have any problems just post a thread or drop us a PM