e6600 overclock help

[jfisher007]

My system specs are as follows:

C2D e6600
Asus p5b-e
mushkin em2-6400 ddr2-800 2 x 2GB (5-5-5-12; 1.8V)
Nvidia GTX 280 1 GB
Thermaltake Kandalf LCS Tower
OCZ GameXtreme 850 W PSU
WD Caviar Black 1TB

I have set up a 1:1 ratio and upped the FSB to 400Mhz and 1.4375V. My system POSTS and boots into windows but prime95 failes instantly with this error:

[Sat May 09 21:06:57 2009]
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.

My temps are creeping up to the 50*C mark with water cooling at that voltage using small fft. Am I doing something wrong? What should I do? I know these e6600 are capable of doing this OC. Any help would be greatly appreciated.

 

[cubeless]

either drop the memory speed or punch the voltage up on the cpu... u may need 1.475 to 1.5 v...

this oc thing of ours is not just given, it is earned...

 

[error8]

You have to up the north bridge, south bridge and vtt voltage. Only increasing the FSB and vcore, doesn't give you too much.

 

[BonzaiDuck]

Originally posted by: error8
You have to up the north bridge, south bridge and vtt voltage. Only increasing the FSB and vcore, doesn't give you too much.

My experience with the E6600 CPU suggested to me that a VCORE setting that resulted in a voltage-SENSOR reading of <= 1.3625V is fundamentally "safe." A set value of 1.4+V may very well generate an idle reading within the spec. I had experimented with an OC setting for VCORE of 1.44V. This may depend on the motherboard and chipset. Obviously, under load conditions, the load voltage reading would be lower than the idle value due to VDroop and VOffset. Others here may tell you that the VID spec for the processor has an upper limit of 1.5V, and that you can push the VCORE setting higher. I tend to be more cautious -- myself.

For these and other processors, you may need to boost the CPU_VTT (also labeled CPU_FSB for some chipsets) above its default as you approach a host-frequency of 400 Mhz.

And while you may also need to boost the NB and SB voltages, my experience with some motherboards suggests that the "auto" or default values for these may already be in excess of necessary. So it is important that you do not simply increase these voltages above the voltage readings for them blindly. Find out what the sensors report under "Auto" and go from there. Intel-chipset-based motherboards may give default NB and SB settings that are not so "excessive."

If you are shooting for a 1:1 ratio and host-frequency of 400Mhz, you should approach it in increments of 5Mhz with incremental adjustments in voltages as necessary. Your PRIME95 temperatures are well within temperature spec for either TCASE or the core sensors. Someone with more experience for the E6600 AND water-cooling might provide better insights.

As for the tedium and time required to get an OC tuning for your system, let me quote what cubeless said:

this oc thing of ours is not just given, it is earned...

You should read Graysky's sticky-thread on OC'ing these cores, if you haven't already done so.

EDIT: PS: P965 chipset, as I see it, is pretty old -- hopefully a reasonable match for the also-dated E6600. You might want to poke around some forums to get an idea which BIOS revision is best. Probably not necessary, but useful.