Hello
I brought my first Q6600 + XFX 680i LT combo from TigerDirect in January, but I could not get the CPU go above the 3.0Ghz because of the 1.325 VID. I needed 1.4V to get the CPU to be stable for 3.0Ghz. The Fan noise from the motherboard also bothers me a lot. After several considerations, I sold the computer with cheap price but still made $300 since I got so many things for free after rebates.
This time I upgraded many components using the extra money I got.
Q6600 G0 1.325VID -> Q6600 G0 1.325VID (Why do I always get the worst?)
Zerotherm BTF90 -> Zerotherm Nirvana NV120
XFX 680i LT -> MSI P7N Diamond
MSI 8800GT OC -> EVGA 8800GTS OC
Adata PC6400 4GB -> OCZ SLI-Edition PC6400 4GB
WD GP 750GB -> WD SE16 640GB
CM Mystique 632S -> Antec Nine Hundred
Antec Earthwatts 500W -> Cooler Master 750W
As you can see, I pretty much upgraded everything and get a complete new system. The Q6600 Batch is L746A. The Antec 900 case provides the best airflow. Other than the included 4 fans (two front, one rear, one top). I also installed a 120mm side fan. The CPU cooler fits nicely in the case, I put the Zerotherm Nirvana to blow the air up, and it also draw airs through the heat pipe of the MSI P7N motherboard. The system turns out much better than I expected in the cooling coordination. The case fan sends cool air in from front and side, and the top fan took out all hot air from the CPU. The CPU fan cools both CPU and NB chip nicely. As a result, I got the 3.0Ghz OC without any problem. All I did was to change the FSB speed and it works at 50C under load.
However, when I try to increase the speed more, I faced serious problems. The P7N Diamond bios is immature and the NB chip has serious problem of FSB hole from 1380 - 1500. I couldn't get the system to boot into Windows no matter what. After trying out all different setting other people posted on the web, I just decided to quit overclock and stay at 3.0Ghz. But the PCSX2 doesn't allow me to do it either. When I try to run FFXII on the emulator, the frame kept skipping and the sound is so horrible. I was forced to keep overclock to higher speed.
Anyway, after all those story and many failure, I finally found a stable setting that can take me to 3.52Ghz even with the worst 1.325VID Q6600. Here is my current setting:
FSB: 1570Mhz
Ram: 800Mhz (Show up as 785Mhz)
Vcore: 1.325VID + 0.200V = 1.525V
VDIMM: 2.10V
VNB: 1.4V
CPU GTL Ref: 70
FSB Term: 63
All other voltages: AUTO
The hottest core runs at 63C when the room temp is 23C under Prime95.
The most significant difference between the recommend setting is the FSB Term. The other thread recommends 25, but I found I have to increase it to the max to get the system stable without reboot. Right now I can finally play the FFXII with better speed. The Vcore is still a little too high for me, but I can't help since I am super bad luck at CPU drawing. I get two 1.325VID CPU two times already. Now I can finally enjoy the computer before the CPU blows up. (Hope not....)
I brought my first Q6600 + XFX 680i LT combo from TigerDirect in January, but I could not get the CPU go above the 3.0Ghz because of the 1.325 VID. I needed 1.4V to get the CPU to be stable for 3.0Ghz. The Fan noise from the motherboard also bothers me a lot. After several considerations, I sold the computer with cheap price but still made $300 since I got so many things for free after rebates.
This time I upgraded many components using the extra money I got.
Q6600 G0 1.325VID -> Q6600 G0 1.325VID (Why do I always get the worst?)
Zerotherm BTF90 -> Zerotherm Nirvana NV120
XFX 680i LT -> MSI P7N Diamond
MSI 8800GT OC -> EVGA 8800GTS OC
Adata PC6400 4GB -> OCZ SLI-Edition PC6400 4GB
WD GP 750GB -> WD SE16 640GB
CM Mystique 632S -> Antec Nine Hundred
Antec Earthwatts 500W -> Cooler Master 750W
As you can see, I pretty much upgraded everything and get a complete new system. The Q6600 Batch is L746A. The Antec 900 case provides the best airflow. Other than the included 4 fans (two front, one rear, one top). I also installed a 120mm side fan. The CPU cooler fits nicely in the case, I put the Zerotherm Nirvana to blow the air up, and it also draw airs through the heat pipe of the MSI P7N motherboard. The system turns out much better than I expected in the cooling coordination. The case fan sends cool air in from front and side, and the top fan took out all hot air from the CPU. The CPU fan cools both CPU and NB chip nicely. As a result, I got the 3.0Ghz OC without any problem. All I did was to change the FSB speed and it works at 50C under load.
However, when I try to increase the speed more, I faced serious problems. The P7N Diamond bios is immature and the NB chip has serious problem of FSB hole from 1380 - 1500. I couldn't get the system to boot into Windows no matter what. After trying out all different setting other people posted on the web, I just decided to quit overclock and stay at 3.0Ghz. But the PCSX2 doesn't allow me to do it either. When I try to run FFXII on the emulator, the frame kept skipping and the sound is so horrible. I was forced to keep overclock to higher speed.
Anyway, after all those story and many failure, I finally found a stable setting that can take me to 3.52Ghz even with the worst 1.325VID Q6600. Here is my current setting:
FSB: 1570Mhz
Ram: 800Mhz (Show up as 785Mhz)
Vcore: 1.325VID + 0.200V = 1.525V
VDIMM: 2.10V
VNB: 1.4V
CPU GTL Ref: 70
FSB Term: 63
All other voltages: AUTO
The hottest core runs at 63C when the room temp is 23C under Prime95.
The most significant difference between the recommend setting is the FSB Term. The other thread recommends 25, but I found I have to increase it to the max to get the system stable without reboot. Right now I can finally play the FFXII with better speed. The Vcore is still a little too high for me, but I can't help since I am super bad luck at CPU drawing. I get two 1.325VID CPU two times already. Now I can finally enjoy the computer before the CPU blows up. (Hope not....)
to the forums ! 
