OC failing at Hard Disk boot

[Odiseo]

Maybe I am missing a detail and you can point me to the right direction

My Hardware is

CPU: Intel Core 2 Quad Q6600 G0
MB: Asus P5KPL-e chipset G31
Mem: 2 x 2G 800MHz Kingston
VGA: Macy Nvidea 512 MB (GPU 450 MHz, Mem 700 MHz, DDR2)
Power Supply: 420 W (heavy one)

So far I reduced voltages Vcore to get minimun disipation, about 1.18 V.
I put PCIE freq fixed to 100 MHz. My Bios dont have FSB: MEM ratio. Instead has and entries for FSB freq and mem Freq separated, a little more convenient.

I put mem Fixed to 800 MHz. Its voltage also fixed to 1.8V as says the memory datasheet.

The North bridge voltage also at minimum 1.5V.

There is a CPU PLL voltage I am not sure what is for, also works at minimum (not auto)

So far it works great at 2.4 GHz, 1060 FSB, 800 MHz mem. Boots perfectly and I can run Prime95 for long time below 40 celsius degrees measured with coretemp. Like factory settings.

My board support 1333 MHz FSB so it is not difficult, with a little increase of CPU voltage to manage the system to reboot and get back to the BIOS setup with out any problem.

FSB 1332 MHz and CPU freq 2.999 Ghz.

Temperature is Ok according to MB monitor, below 40 degrees without any stress.


As soon as eave BIOS setup and it tries to boot from disk it may get further or not but eventually crashes before vista loads completely.

I have read here that PCI freq (not just PCIe) freq is very important for onboard Sata controller and must be 33 MHz.

So far I can not find a related option in my BIOs for it. I do have read all around that this is very important.

Have your ever ran into a similar problem?

Is there anything else I am missing?



Thanks in advance!

 

[Odiseo]

Later I did this test:

I increased the North Bridge voltage.

Also I noticed that when I change FSB freq, Mem freq changes a little crazy.

When I set 333 (1333 , an aparent feature of this bios) the mem freq changes to 999 for the same ratio

then I change to the closest ratio to 800, like my mems and it is 832.

Even though it boots up to BIOS it can not start Windows from disk

I tried not to push it so hard and set fsb freq to 300 (1200 fsb) and it gave me the choice of 750 for mem.

Then it boot from disk and I had to increase cpu voltage to 1.2 for stability

Then checked temps for prime95 and coretemp and they rose to 50c

(room temp 25c and I forgot to mention before I have a Big HSF with Fan)

CPUz confirmed ram speed 375 (750)

CPU speed was (9*300) 2700 MHz with (4*300) 1200 FSB

I still have no idea what CPU PLL voltage is for. I searched some posts but it is a sort of empirical item I think.

I will try to push it a little further later. I am just hesitating because my kingston mem specs says it will not allow voltage increase over +.1 V. Maybe it is too risky for me, I have no spare

Any ideas ?

 

[Odiseo]

... well I guess nobody ran into this kind of Asus BIOS without PCI frequency option

 

[Odiseo]

wrong forum