Exact voltage for core 2 quad q8400 overclock to 3 8 GHZ

[mbmz]

Hello,
what is the exact voltage to overclock a core2 quad q8400 to 3.8 and 4GHz.
Motherboard: Gigabyte EP45- UD3R
CPU cooler: Xigmatek Dark Knight
5 GB RAM
320 GB Hard disk
Graphics Card: ATI Radeon HD4670 GDDR3 512 MB

 

[festerovic]

There is no exact voltage, ever, on any chip. It depends on the chip. It might even be done on stock voltage.

 

[cromedome]

Different chip= different voltage.. Different chip also means that there is not a 100% you will get 4.0ghz (even with custom water etc)

 

[mbmz]

When I take my PC to 4 GHz it does not turn on. and at 3.8 GHz it hangs after 20 mins of OCCT. (at stock voltage). I hav tried 1.35V with 4.0 GHz but no change. What might be the reason for this?? Currently running at 3.76 GHz. Temperatures were 65-68'C with 1 hour OCCT.

 

[festerovic]

I think you asking alot from a quad core, trying to push it to 4ghz. Quad core chips don't OC quite as high as a dual core of the same family.

Now, you also need to check the other voltages on the board, try raising them too. That way you can reduce the variables that are causing it to fail. IMO, If you have tried 1.35v and can't get what you want, I think you may have hit the limit on your particular chip. I believe that's the max voltage (unless you want to gamble) for that chip. From 2.6 to 3.76ghz isn't too shabby, you should be stoked.

 

[jaquith]

First, what "are" your multiplier settings??
[BCLK, CPU Multiplier, Memory Multiplier, UCLK, QPI]

If you are running 4.xGHz without changing at least your CPU, DRAM Bus & QPI/DRAM voltages then I'm certain you'll fail Prime95 in a matter of minutes with 80C+.

You can try the following, but it is a trial by no-post process:

CPU Voltages
LoadLine Calibration.......................Level 2
CPU Vcore..................................1.33750
QPI/VTT Voltage............................1.335
CPU PLL....................................1.860

MCH/ICH Voltrage
PCIE.......................................Auto
QPI PLL....................................1.100
IOH Core...................................1.120
ICH I/O....................................Auto
ICH Core...................................Auto

Dram
DRAM Voltage...............................1.600
DRAM Termination...........................0.780
Ch-A Data VRef.............................0.780
Ch-B Data VRef.............................0.780
Ch-C Data VRef.............................0.780
Ch-A Address VRef..........................0.780
Ch-B Address VRef..........................0.780
Ch-C Address VRef..........................0.780

 

[RJR]

Hello,
what is the exact voltage to overclock a core2 quad q8400 to 3.8 and 4GHz.
Motherboard: Gigabyte EP45- UD3R
CPU cooler: Xigmatek Dark Knight
5 GB RAM
320 GB Hard disk
Graphics Card: ATI Radeon HD4670 GDDR3 512 MB

4.0 Ghz with a Q8400 is really pushing it as you are finding out. You are going to have to push your MCH(NB) voltages and FSB termination voltage as well as set your GTL Ref voltages to even have a chance.

Could you post a screen shot of Cpu-z (CPU (idle and load) and memory) so we have an idea of idle vs load (vdroop) and memory speed?

 

[mbmz]

Best answer selected by mbmz.

 

[RJR]

I hope you realize that the configuration Jaquith gave you is for a completely different kind of computer (i7) with all different options so those voltages won't work at all in your computer and will likely do some harm if you try them.

 

[mbmz]

4.0 Ghz with a Q8400 is really pushing it as you are finding out. You are going to have to push your MCH(NB) voltages and FSB termination voltage as well as set your GTL Ref voltages to even have a chance.

Could you post a screen shot of Cpu-z (CPU (idle and load) and memory) so we have an idea of idle vs load (vdroop) and memory speed?

Here are the links to CPU Z and Coretemp screenshots

 

[mbmz]

First, what "are" your multiplier settings??
[BCLK, CPU Multiplier, Memory Multiplier, UCLK, QPI]

If you are running 4.xGHz without changing at least your CPU, DRAM Bus & QPI/DRAM voltages then I'm certain you'll fail Prime95 in a matter of minutes with 80C+.

You can try the following, but it is a trial by no-post process:

CPU Voltages
LoadLine Calibration.......................Level 2
CPU Vcore..................................1.33750
QPI/VTT Voltage............................1.335
CPU PLL....................................1.860

MCH/ICH Voltrage
PCIE.......................................Auto
QPI PLL....................................1.100
IOH Core...................................1.120
ICH I/O....................................Auto
ICH Core...................................Auto

Dram
DRAM Voltage...............................1.600
DRAM Termination...........................0.780
Ch-A Data VRef.............................0.780
Ch-B Data VRef.............................0.780
Ch-C Data VRef.............................0.780
Ch-A Address VRef..........................0.780
Ch-B Address VRef..........................0.780
Ch-C Address VRef..........................0.780

My processor is: Core2 Quad Q8400
Motherboard: Gigabyte EP45- UD3R

I dont hav the options:

QPI/VTT Voltage
PCIE
QPI PLL
IOH Core

DRAM Termination
Ch-C Data VRef
Ch-A Address VRe
fCh-B Address VReef
Ch-C Address VReRef

 

[55Range]

hmm, well i oced my Q 8400 at 3.6 ghz at only 1.3 vcore. hyper 212 + w/o temps goin over 60

 

[venjhammet]

hmm, well i oced my Q 8400 at 3.6 ghz at only 1.3 vcore. hyper 212 + w/o temps goin over 60

Can you please tell me how did you manage to make it to 3.6ghz? I Oc my Q8400 but I never went futher than 3.2ghz with everything on stock/auto. My mobo is P5Q SE Plus, I know this board is good for overclocking but I'm a newbie to this thing. Hope you can guide me here. Thanks.