i7 950 4.0ghz stability problem!

[Kai`]

Hey guys I'm new to overclocking, and after reading several threads on here I've finally taken the plunge and overclocked my i7 950 to 4.0ghz.

However, i think I'm starting to have stability issues - I initially tested for stability with 25 runs of LinX and it passed so I proceeded to run hyper pi 32m (which also passed) as well as super pi (32m), cinebench CPU and 3d mark vantage. These all passed, I then decided to run 50 passes just to be safe, and much to my surprise I failed on the 34th pass.

My question is now, what can I do to make my overclock more stable?

Running on a Gigabyte x58a-UD3r rev 2.0 mobo
Currently my bios settings are:
Bios Settings:
CPU Clock ratio @ 23
QPI Clock ratio x36 (QPI link speed at 6.26ghz)
Uncore clock ratio - 17
Base clock - 174
System memory multiplier (SPD) - 8 (results in 1392 memory frequency)
Load Line Calibration - Level 2
CPU Vcore - 1.32500v
QPI/vtt voltage - 1.335
CPU Pll - 1.80
QPI Pll - 1.24
IOH Core - 1.2
ICH 1/O - Auto
ICH Core - 1.2
DRAM - 1.66
ram settings at 9-9-9-24 2t

Would appreciate it someone could offer me some advice to help solve this!

 

[BigTerminator]

Try lowering the Vcore to 1.275,you are adding too much. Disable Spread Spectrum if you have that option. Up the CPU PLL and what exact memory are you using? What cooling do you have, it could have overheated. Is the QPI Multi as low as possible?

 

[Kai`]

Hey, thanks for the reply.
Im using a noctua DH14 (with its stock push pull fan config) in a coolermaster HAF 932, temps dont exceed 77 degrees under load. I also have corsair XMS3 ddr3 1600mhz.

I have tried lowering vcore but it just results in failing linx faster.

Would a cpu pll of 1.88 be ok?

 

[BigTerminator]

Ummm... It can hurt to try that but I'm not sure what exactly is you instability. Make sure your memory is running XMP and at 1600mhz using 200x20 multiplier bclk combo.

 

[Kai`]

will give those a try, thanks.