Help! Overclocking Q9400 / P5QL-VM-EPU

Hi all,

I need a little help with a system that I am attempting to overclock just a little more. I am not new to overclocking, especially these lga775 systems, but this one has me stumped.

History on the bios version: this is an Asus Essentio cm5570 system, a complete tower, sold retail with the motherboard P5QL-VM EPU with a bios that cannot be overclocked. The board, however, can be flashed with the 0601 bios, so now it has overclocking options showing in bios and it can be overclocked.

Specs are as followed:
CPU: Q9400, overclocked from 2.66ghz to 2.89ghz
Mobo: Asus P5QL-VM EPU from an Asus cm5570, with 0601 bios flashed to make this non overclockable bios, able to be overclocked.
Ram: dual channel 8gb ddr2@800mhz.
PSU: evga 600w
GPU: gtx750ti

This pc was pieced together for a console loving brother of mine to break him into the PC world.

I have been able to overclock this so far from 2.66ghz to 2.89ghz. The problem is, at 2.89ghz, this thing is crazy stable. No crashing at all after long gaming sessions and prime 95 for several hours, so I would think it could do more. Just baffles me that with just 1 increment change on the FSB, it won't boot without overclock failed screen. The FSB is 360 which places it at its 2.89ghz. If I bump the FSB to 361, the PC boots to a screen that advises that the overclock failed.

I have loosened ram timings, increased vcore, northbridge, and ram voltage, still boots to overclocked failed screen when the FSB is 361. I maxed all voltages(safe max) for vcore, ram, and north ridge, just to see if I could increase the FSB 1 more increment - this is what makes me think its ram timings that cause the issue.

Just seems to be a little strange that this system is incredibly stable and cool at FSB: 360, @ 2.89ghz but with one increment on the FSB and it boots with an error. I would think that increasing the FSB should allow it to boot and run, until I begin to get crashing, then I can lower FSB or raise voltage, accordingly.

Any help is appreciated as to what to put these settings at to squeeze a little more out of this. 3.0+ghz would be awesome to get a little more performance for my brothers gaming.

To note, the vcore can only be raised in +50mv up to +150mv.

thanks all for any info that may help us out.

The link below will take you to my other thread at overclock.net, because there are screenshots of my bios there so you can see what options I can possibly change. Thanks you.

www.overclock.net/t/1613896/help-q9400-asus-p5ql-overclock-issues#post_25588915

Have you tried dropping the memory frequency? Or a different strap

Johan45 said:

Have you tried dropping the memory frequency? Or a different strap

Click to expand...

I don't see an option to change the strap, however, I have changed the memory freq from auto and changed to other frequencies, including dropping it.

Set the FSB-to-RAM ratio to 1:1. (Run the RAM at the same clock as the FSB)

RJARRRPCGP said:

Set the FSB-to-RAM ratio to 1:1. (Run the RAM at the same clock as the FSB)

Click to expand...

Ok, I set the ram freq to same as FSB. (360 FSB = 720mhz ram) boots no issues. Then tried FSB: 361, made ram freq 722, and loads to overclock failed screen.

Can you post some info about your ram? Make, model, voltage, speed and timings. Are all the sticks the same? CPUz screen shots of spd screens for the different sticks and one of current memory settings.

I’ve played with three different P5Qs and all three were quirky.

If you haven’t tried it yet, add ten or twenty to the FSB beyond what stated as I remember, (?) some boards had blank spots.

8GB is a lot of RAM, assuming 4x2 try 2x2 a lot of the socket 775 MBs had problems pushing 4 sticks.

If you have the ability to adjust performance level in BIOS try 9, 10 or 11, (Asus Ai Transaction Booster), the P5Q WS I’m playing with now doesn’t like anything tighter than 9 with 1:1 ratio and Asus boards on Auto have a tendency to set it to tight as I remember or maybe too loose.

Last try SetFSB (PLL=ICS9LPRS918BKL) and see if passing 360 in Windows works also MemSet will help with testing memory settings.

Aleslammer said:

I’ve played with three different P5Qs and all three were quirky.

If you haven’t tried it yet, add ten or twenty to the FSB beyond what stated as I remember, (?) some boards had blank spots.

8GB is a lot of RAM, assuming 4x2 try 2x2 a lot of the socket 775 MBs had problems pushing 4 sticks.

If you have the ability to adjust performance level in BIOS try 9, 10 or 11, (Asus Ai Transaction Booster), the P5Q WS I’m playing with now doesn’t like anything tighter than 9 with 1:1 ratio and Asus boards on Auto have a tendency to set it to tight as I remember or maybe too loose.

Last try SetFSB (PLL=ICS9LPRS918BKL) and see if passing 360 in Windows works also MemSet will help with testing memory settings.

Click to expand...

You should use 1.90 V VDIMM for 4 sticks...