Minimal OC, surely can get better?

[alastairadb10]

Hi,

Have been attempting to OC Q6600(GO) on ASUS P5N-E Sli board, 4*1Gb DDR2 800 Ram. Reasonable Akasa HS/fan (but temp is not my probem at the moment...)

My problem is that I cant get an OC greater than 2588MHz (2400 stock).
FSB>288MHz, X9 and get past BIOS spash screen but have an "exception" text screen which doesnt say anything useful. After a moment it will auto reboot with former working parmeters

What ive done:
Everything in BIOS that can be dissabled has been.
Everything apart from below (voltages etc) on auto.
Downclocked RAM (till CPU OC done), 4-4-4-12 (395MHz, DDR2)
initially linked FSB QDR and DDR as 1:1 (and could OC to FSB of 288MHz)
After unlinked FSB QDR and DDR, left DDR at downclocked vals and tried to increase CPU FSB > 288 - same problem.

Temps are fine vcore seems low. I have a (seperate?) suspicious problem that I cannot have all 4 RAM sticks in at once when set at 800MHz but can be at 800 when theres three. Boots if all 4 are at 667. individual memory sticks, slots tested and ok. Memtest86 run for 12h and reports all is fine. I am thinking there is a power problem. When all 4 stick in at 800Mhz cant get into BIOS as keyboard (and monitor!) dont seem to have power, cant press del...I am happy to run with three sticks but think this may be related. PSU is 500W but suspect its the problem...(inefficient/damaged).

Any help would be great. i find it hard to believe 2588 is as good as it gets! (i know all chips are different)

Max Temp under load 44C, Vcore 1.216-1.221 (auto)

 

[Lupiron]

You have a 6xxi chipset with a q6xxx processor. Those naturally dont want to OC high together!

Its safe to put the RAM on auto, so it boots with 5-5-5-15 @ 1.8 volts. That way you know there isnt a problem with the RAM.

I dont know about your ram, some say that they are unable to OC with 4 sticks, though I always use 4 sticks and there hasnt been a problem that I can see. Its the FSB on those boards, usually.

You'll have to hunt around until you find one where you can at least post, then hope it boots! Mine was 1485 FSB and it booted. Other than that, at 2.88 and higher, it wouldnt even Post. Then at 1485 it did!

Try x 8 multi, 400 FSB, North Bridge set to 1.4, cpu pll voltage to 1.5, VCore to 1.4. Thats 3.2 ghz for the processor, and you will be able to sync up your ram near that!

But, it prolly wont post for you, so play around near that FSB, try 405, 410, etc, hopefully one will post, and then you can lower the vcore if needed and such!

--Lupi

 

[Evilonigiri]

I have seen people that thought they're ram were stable but in fact wasn't.

To make sure this isn't the case, set your FSB to 266MHz and cpu to x9 (after disabling all the options you need to disable, refer to OCing guide here if you don't know). Then leave vcore on auto. With all the NB and FSB voltage on auto or normal, set timings to 4-4-4-12 at 800MHz using 2V, so that means a 2:3 ratio or a system memory multiplier of 3. Run Orthos or Prime blend test for 24hours, to make sure the ram is completely stable.

After you have determined that the ram is stable at those settings, set the FSB to 333MHz with a cpu multiplier of x9 with vcore left on auto. Set the ram to 5:6, or a memory multiplier of 2.4. This way you can maintain the 4-4-4-12 800MHz using 2V. All other voltages are left on auto or normal. With this, your system will boot successfully. If it doesn't, you may conclude that the motherboard and/or cpu is a lemon, the PSU is of poor quality, and/or simply your Q6600 is not very compatible to the 6xxi motherboard.