Problems with new build GA-Z77X-UD3H

[oldpaint]

I recently built a computer using a gigabyte GA-Z77X-UD3H (F-11, later F-17 bios) motherboard with a i5 2500k processor, Hyper 212 EVO, Gskill Ripjaws 8gb 9 9 9 24 2t 1600, samsung ssd 830 series 256gb, thermaltake 675 watt psu, EVGA GTX 680 SC. It runs fine...until I try to OC it. The first problem I noticed was when I set the multiplier to 45 (4.5Ghz OC) and left the vcore on auto. The core temp on the hottest core hit 98C a few seconds after starting the prime 95 blend test and vcore had climbed to over 1.5 according to cpuz. I shut down prime 95 and did some experimenting and found that setting vcore to 1.280 was enough to run prime 95 stable for about 12 hours with max core temp at 68C at 4.5Ghz. At this point I had enabled XMP and the memory was running at 9 9 9 24 2t 1.5v, vcore was set manually to 1.280v, multiplier at 45 and running stable. Then I started having random boot-loop problems when ever starting from a cold boot, but no problem when restarting. I reloaded optimized defaults and no boot loops. Then I changed only the multiplier to 38, 100Mhz above stock turbo, and the boot loop started again. I rma'd the motherboard and it made no difference. I finally found a solution to this but it seems something with the motherboard is definitely bugged to cause this problem. The solution was to disable C1E and C3/C6. I also disabled turbo and left EIST enabled. I have googled "boot loop" and it seems gigabyte boards are the only ones plagued with this problem. Are there any consequences to running with C1E and C3/C6 disabled?

edit: changed 2600k to 2500k

[wazza300]

i wouldnt leave cpu voltage on auto,set it to normal and add a tiny amount on dvid,try +0.0010v,try with dram voltage at 1.55v too,keep all c states and eist enabled it shouldnt affect stability,then test with prime95 to see if its stable and dont let cpu volts and temps go to high

try with llc level at high or medium

[oldpaint]

I set vcore to normal and when running prime 95 vcore shot up to 1.524 and core temp back to 98C in a matter of seconds.

[oldpaint]

I wasn't running vcore at auto anymore it is now set at 1.280, but auto and normal seem to be the same. Maybe this board is not compatible with Sandy Bridge, at least not compatible with OC'd Sandy Bridge.

[wazza300]

it should shoot up that high,it depends on the llc levels but idk why its doing it,could be because its sb cpu idk,you can try with the lowest or no llc and undervolt the cpu in dvid with -0.0500v

[oldpaint]

When I set vcore to 1.280 in the bios it drops to 1.272 on prime 95 (v-droop). I set llc to high and it acts the same as auto (1.272 on prime 95) where I have it now. If I set llc to turbo it runs at 1.284 on prime 95. When setting vcore manually to a number it disables (grays-out) dvid. I think the bios is bugged, or not compatible with running sandy OC'd. Disabling C1E and C3/C6 state in the bios works as far as ending the boot-loop problem. So I think it's some kind of voltage related issue with the bios in relation to sandy bridge. C1 and C3/C6 are some kind of energy saving features that must be causing a lack of proper voltage to ensure stability when starting from a cold boot (while OC'd) related to sandy bridge.

[oldpaint]

Before I figured out to disable C1 and C3/C6 it would boot loop a bunch of times and either eventually boot or a message box would pop up saying boot failure and prompting me to set optimized defaults and reboot or enter bios. If I entered bios and then exit and reboot it would then boot normally. After booting it would then be stable and normal even in prime 95 for 12 hours. Sometimes it would cold boot normally anyway. 50% of the time I would get the boot loop from a cold boot but never from restarting windows.

[wazza300]

It helps to have both BIOS chips running the same version of BIOS,to flash the back up with the main press and spam the alt and f10 keys at splash screen,also manually type in the bclk to 100

[oldpaint]

I flashed the backup bios and the main bios on the first motherboard but it didn't make any difference so I haven't bothered to do it on this one. I don't know if spamming the alt f10 keys at splash screen would make any difference, but I shouldn't have to do that in order to boot normally. As far as manually setting the bclk to 100, I already tried that with no luck.

[wazza300]

it supposed to help with double booting having both chips the same bios version,i know its a pain but idk why its overvolting your cpu either,should be a simple setup with dvid