Quote Originally Posted by xarot View Post
Hi,

I've been browsing these forums for some time but now it's the time to make the first post.

I've been having massive problems OC'ing this board. I've tried QX6700 and now I have QX9650. I've got it stable only by OC'ing with the multiplier (QX6700 @ 11*266 = 2933 MHz, QX9650 @ 10*333 = 3333 MHz). For example if I try to OC the QX9650 further to 10*350 = 3500 MHz, it isn't prime stable anymore, one core failed after 2 hours. I could run at 10*333 without touching any voltages, but at 10*350 I tried the following:

CPU voltage 1.3 .. 1.35 V
CPU PLL 1.6 V
CPU VTT 1.28 V
MEM 2.1 V
NB Core 1.40 .. 1.44 V
SB Core 1.5 V
1.2 V HT 1.35 V
Bridge Core AUTO
CPU GTLREF +30 mV
NB GTLREF +30 mV

the rest is AUTO.

..and it's still unstable.

I have managed to boot to Windows at 10*400 by upping the voltages further but it's not stable at all. Do I have the GTLREF voltages wrong? If I use 1.28 V on VTT, should I actually use CPU GTLREF -5 mV?? That doesn't help at all..

I also wonder does the SLI make things harder to overclock? When I tried 3-way 8800 Ultra's, I couldn't always even post when I tried to OC, but with 2-way SLI, It's much easier. Could be related to the PSU, too..

Here are my specs:

Corsair HX620
Striker II Formula 1701 BIOS
QX9650 with Noctua NH-U12P
4 sticks of Corsair XMS2 6400 C4 (tried with 2 sticks - didn't help)
8800 Ultra OC SLI
Seagate 1 TB
etc..


This QX9650 has been tested by previous owner at 5.4 GHz with a "proper" mb..

Hopefully someone could help me. I think the QX9650 at only 3.33 is holding the Ultra's back a bit.
You should be getting 4.0 GHz without having to touch any gtlref voltages. Also I recon you need to do your maths on the power supply. Overclocking a quad and running 2 let alone 3 8800 Ultra's on a 620w PS is simply not going to work. I'd try going back to 1 GFX card and 2 sticks of ram. 3 GFX cards load up the southbridge so 1.6v are needed there for a start. Also try about 1.4v vcore in bios with loadline enabled just to see how it responds. That will not damage anything but I would find a voltage that you are happy with for normal use. Those voltage at 400x9 should work easy. If they don't, I'd be lookiing for another board.