I'm not really an expert on any of this, so bear with me.
I've got a 2+ yr old computer that I recently decided is due a clean wipe and fresh install of win7 (previously had vista)
Q6600 @ 2.4ghz
ASUS ROG Ramgage Extreme
300gb velociraptor 10000rpm
500gb western digital 7200rpm
antec signature 850w
tunic cpu cooler
antec twelve hundred case
I formatted the drives, installed windows, installed drivers, set up cpu-z, hwmonitor, prime95, etc. Everything worked fine, booted quick, looked good.
I previously had this cpu overclocked to 3.5ghz using the automated ROG cpu upgrade feature in the BIOS. Never had problems with it, ran 24/7 on air with cool temps (idle ~30c give or take) for at least 2 years. So I was just going to return it to that overclock and call it good. Always worked for me in the past and I'm all thumbs when it comes to manually setting values for frequencies and timings and voltages and all that, so the automated cpu upgrade feature is awesome for me.
When I booted the BIOS and set it up like it was before, I started getting failed overclocks, so I bumped it down a notch and windows finally loaded, but after about 5-10 minutes at idle, I started getting weird lines on the screen. Sometimes they were wide and vertical, only a couple of white-ish lines. Then I had lots of horizontal thin lines. I tried rebooting but my BIOS wouldn't post. Had to turn it off at the PSU. I got it to post and entered BIOS and reset it to factory clock and that's the only thing that seems to NOT create the lines.
At first, I thought GPU, but I have the most up to date driver and catalyst control center. Temps on the card were fine as well. And why would it be the GPU if the lines were the result of a CPU overclock? I dunno. I'm stuck and have no idea what to do. I left it at stock clocks and it ran over night with no issues. Haven't tried any load testing or anything because it seems pointless until I can figure out what's wrong, fix it, then try and overclock again.
Does anyone have any idea what might be causing this?