Help Overclocking Q6600

Hi all,

Just wondering if there is anyone out there who has overclocked a Q6600 using an Asus P5n-D mobo?
I have tried loads of combinations of Voltages but when i do get into windows my computer restarts randomly!

The VID of my processor is 1.325V and batch no is: L837B640

So far the most stable combination is FSB 1333 - in order to reach 3.0Ghz, Dram voltage - 1.85v, HT - 1.4, NB - 1.44, SB - 1.5.

using this combination i ran prime95 for 6 hours with no errors but when i run a game or media player the computer restarts itself.

Temperatures do not seem to be the problem as under full load on prime95 my cpu hits max of 55 OC.

If anyone has any suggestions what settings to try please let me know.

My Rig:

O/S: Windows Vista Ultimate 64bit
Mobo: Asus P5N-D
CPU: Intel Q6600 G0 2.4 GHz
Cooling: Air (CPU cooled with Asus Silent Knight II)
Graphics: BFG GeForce 9800GTX DDR3 512MB
RAM: 8GB (4x2GB) OCZ 800Mhz DDR2 Gaming RAM
PSU: OCZ Silencer 750 Watt
Case: Antec 902
Mouse: Logitec G5 Gaming Mouse
Keyboard: Razor Tarantula Gaming borad
Monitor: BlueH 22" TFT
Sound: Soundblaster Audioligy 7.1 Surround sound

did you check to see what your memory multiplier was set at? If it wasn't set properly your ram might be running out of specs and at 1.85V to the ram probably wasn't enough juice to let it run at the speed. Also did you prime95 or use IBT to test stability of your system?

The CPU multiplier is 9.0 x 333.3 Mhz, the FSBRAM ratio is set at 5:6

My RAM is rated at 1.8 volts but it says it will allow 1.9volts

i used prime95 to run stability test.

should i disable C1 and speedstep? dont know if this will make much difference.

is it safe to increase memory voltage past 1.9? or will problem lay somewhere with the other voltages? Vcore currently at 1.325v

dissable c1 - speedstep will just throttle your speed when your pc is idling, to save power.

have you tried 8x 400FSB? (reach 3.2Ghz) with my q6600 i've always found that keeping the multiplier low-ish helps stability.

EDIT: my first overclock, i let the memory run 1:1 with my processor, with all memory related things on auto. when i got it stable i then adjusted the memory from there.)

I would run memtest for couple passes and see if the memory is at fault. If it is i would up the juice, depending on what sticks you got it should be able to handle atleast 2.0

Right, i will disable C1 and speedstep. will also try changing multiplier to 8 x 400.

How do i change the FSBRAM ratio? dont seem to be able to find the option in BIOS, is it the LSB setting?

What does the FSBRAM ratio actually do? i have not ever touched on changing memory settings have always left them on auto, my memory is OCZ 2gb sticks @ 800mhz (x4 for 8GB). OCZ say it runs at 1.8V but can increase to 1.9V without invalidating the warranty.

Does memtest come in a version to test 64bit O/S as i tried it only for it to say it was only compatable with 32bit O/S.

What is a good voltage to increase memory to?

Monkey_Bum44 said:

Right, i will disable C1 and speedstep. will also try changing multiplier to 8 x 400.

How do i change the FSBRAM ratio? dont seem to be able to find the option in BIOS, is it the LSB setting?

What does the FSBRAM ratio actually do? i have not ever touched on changing memory settings have always left them on auto, my memory is OCZ 2gb sticks @ 800mhz (x4 for 8GB). OCZ say it runs at 1.8V but can increase to 1.9V without invalidating the warranty.

Does memtest come in a version to test 64bit O/S as i tried it only for it to say it was only compatable with 32bit O/S.

What is a good voltage to increase memory to?

Click to expand...

the FSBram ratio gives you a ratio between your FSB and your ram. Say a 4:5 ratio is set. For every 4 MHz your FSB is at your ram would be at 5Mhz, so if your ram was set to 4:5 and your FSB was at 400
400/4 * 5 = 500MHz, that would put your ram at 1000MHz which would be out specs since yours is rated at 800MHz DDR2 which is 400MHz actual speed. The memory setting should look like 2.00D, B, C, A or whatever in bios.

do the current settings I have for my HT, NB, ST and vcore look about right? currently HT is 1.4v NB is 1.44v SB is 1.5v and vcore is 1.325v

Monkey_Bum44 said:

do the current settings I have for my HT, NB, ST and vcore look about right? currently HT is 1.4v NB is 1.44v SB is 1.5v and vcore is 1.325v

Click to expand...

personally I wouldn't mess with those and leave those on auto for now. I am able to get to 3.6GHz with leaving those on auto and only changing the Vcore, and ram voltage. your ram should be within specs right now, but the cpu voltage you might be supplying might not be enough. Bios vcore is off, you may have it set for 1.325 but it might be 1.29 use something like cpuz to see the voltage.

Hi,

I have tried a few combinations of the suggestions you all have made,

I am only able to get to 2.6Ghz with only changing the FSB and RAM Voltages.
Anything higher and it refuses to boot.

If i make slight changes to the NT,NB and ST and disable C1 and speedstep i am able to get to 3.0Ghz

Currently i have got:

Vcore @ 1.368v
DRAM @ 1.91v
NT @ 1.44v
NB @ 1.4v
ST @ 1.5v
multiplier @ x9
FSB set to 1333mhz giving actual FSB of 333.3
FSB|RAM 5:4

The system seems stable, was able to run prime95 for 8 hours no probs and temps not going over 50oC

But PC rebooted randomly?? not sure why, maybe need to increase NT, NB ST voltages??

As somebody mentioned before, try changing the FSB/RAM ratio to 1:1 and test stability (leave your other settings the same--this will run the RAM at 333 MHz). If it's stable, then you know your system is having a hard time running your 4 sticks of memory at 400 MHz. Overclocking with 4 DIMMs tends to be much more difficult than when running with 2, so might have to lower your expectations.

Also, get the version of Memtest86+ that runs from a bootable CD. You want to test the memory outside of Windows.

Thanks for suggestion, i was starting to think that the memory was the problem.
I have never really played with the memory settings: timings and such, although they are all set on auto CPUZ says my memory is running 6,6,6,18,24,2T @ 400mhz.
Just a question if i change the FSB|RAM to 1:1 the memeory setting will be 1333, the same as the CPU, i know that this is not the actual speed and that it will be 333.3. Why does it show as 1333 in BIOS?
Do i need to alter the memory timings to run with 333mhz or will BIOS do that for me if i leave it on auto?
Thanks

I would also try to up the voltage. Not all chips are the same, several other members on the board have better G0 Q6600 and can reach 3.6GHz with less than 1.35V while mine takes 1.39 to reach 3.6GHz. You might need to push it past 1.4V to see 3.6GHz. Put the FSB:Ram ratio to 1:1 and then put 400MHz as FSB and raise the volts to the Vcore. Test for maximum clock right now on your cpu. Once you have that we can start testing ram. Is Auto your 1:1 ratio? if so ram will run at 333Mhz which is 667MHz not 1333. memory only has a multiplier of 2, not 4 like the cpu. 1333/4 = 333FSB for cpu 667/2 = 333FSB RAM. If when put at auto and memory shows at 1333 then you are not on a 1:1 FSB: Dram ratio.

ok i have set my ratio to 1:1 with both running at 667mhz, cpu speed has dropped to 1.5Ghz
what setting do i need to run 1:1 cpu at 3.0Ghz and RAM at 333mhz?
when i set FSB to 1333 ram is also at 1333?

I know it's confusing, because motherboard manufacturers use different terminology to describe the various settings. Basically, when we refer to FSB/RAM ratio, it's really the ratio of the CPU reference clock to the memory clock. FSB speed is 4x the reference clock (hence the "quad pumped" Intel term). Memory speed is 2x the reference clock (double-data rate). If you set the FSB/RAM ratio to 1:1, then the RAM will run at a speed equal to the CPU reference clock. So, at 9x333, the memory will run at 333 MHz (666 MHz double-data rate).

I know somebody told you otherwise, but I don't think it's a good idea to start with the 8x multiplier and use a higher FSB. Setting a higher FSB with lower multiplier puts more stress on the chipset and runs the memory faster. To find the limit of your CPU, use the 9x multiplier and set the FSB/Memory ratio to 1:1. The greatest performance benefit comes from overclocking the CPU, so that should be your focus. Once you find the limit of your CPU, you can focus on overclocking the RAM and playing with the 8x multiplier and higher FSB.

EDIT: I don't understand your last post. You should set the CPU to 9x333 and the RAM ratio to 1:1. Please clarify the settings you are using, and give the terminology used in your motherboard's BIOS.

sounds like to me some how your multi dropped? Changing the FSB: Dram ratio should not change your multi, you should still be at 9x333 for CPU speed and your ram should be at 333 as well. If possible a picture of the screen on your bios would help tremendously.

Okay I was able to google up an image of P5N-E bios. Seems like you have the option to run the memory in linked or unlinked mode. Try using unlinked mode and setting the Memory to 800MHz this would put your ram within specs and then you can worry about it later and focus on max clocks. Then try upping vcore voltage and seeing how stable you are at 400x9.

Thanks for explaining the different terminology! why cant they just use the same across the board!
Anyways i have now got a 1:1 ratio, FSB running 333mhz showing 3.0Ghz and RAM running 667 Mhz showing 333.3mhz with timings of 5,5,5,15,20,2T.

I had to set NB @ 1.32v, HT @ 1.34v and SB @ 1.5v to get it to boot, wont boot by just altering Vcore and DRAM voltages.

Happy with that then, whats the best way to test the stability now, run prime? or should i concentrate on testing the memory using memtest86

also the reason why it wont' boot higher with just a vcore increase is the board has a big vdroop from what i've googled by other ocer's on the net. Some had to set the voltage to as high as 1.51V in bios to get a stable vcore for 3.6GHz. You shouldn't need to run memtest if your ram is running under its supposed specs.

Not stable, boots fine but when a game is started system restarts.
Will try upping voltages a little to Vcore, Nb, Sb, Ht.
any other suggestions?

Run Prime95 (with 4 execution threads). If that fails within a few hours, then test the memory using Memtest86+.

This may seem like an obvious question, but I didn't see you mention it anywhere: Is this system completely stable running stock speeds (all settings on Auto)?