Since a few days I replaced my E8400 with a E8600 (Q822A435, VID 1.21v) due to a lack of OC possibilities. According to the batchnumber this should be a great CPU to OC. However I'm having difficulties to get things stable. I think it could have something to do with GTL settings. In general I understand to principal after reading thetechrepository.com and some other site.

I found that I can boot to 610FSB with everything on auto settings, except for dynamic read / write and spread spectrums. I want 450FSB to get my DDR3 to run at 1:2 divider. With still everything on auto I can boot into Windows and CPU-z reports 1.32v but it is far from stable with orthos. I started fiddling around with VTT, vNB and higher vcore (up to 1.41v in bios) without much succes.

Help would be much appreciated.

Quote Originally Posted by Dee View Post
OK, I think I'm starting to get it. I'm running an E8600, btw. I have two GTL options in my BIOS, (0/2) which defaults to 0.63, and (1/3) which defaults to 0.67. What starting point would you recommend for tweaking these? vTT doesn't usually exceed 1.26v. I also have NB GTL reference which I leave at Auto. I would love to OC my CPU higher but it needs lots of vCore (1.4v for 4.33GHz, which is below average for this chip).
I got the same options in my bios but how the hell did you find out what your default GTL values are? And how high your VTT really is?