E6300 Overclocking - Crashing GPU drivers

[thefuryx]

Hello, Im trying to overclock my E6300 (1,87 GHz stock).
The problem is: Im currently working with stable overclock at 2,1GHz (300 FSB, 7x multiplier, stock voltages) but when i rise the FSB over 320, my video drivers keep crashing and restarting. Until I installed the 64bit version of W7 Ultimate I had w7 Ultimate x86 and was able to achieve stable overclock around 2,45 GHz on stock voltages (if i remember it was 350 or 360 FSB and 7x multiplied on stock voltages). Only thing I switch on my HW was replacing older 1GB Kingston memory (DDR2 667) for 2GB Kingston (DDR2 800 CL6) so I could get more system memory and matching frequency of the sticks. I suspect a weak PSU since at least 475W is recommended but i checked few PSU calulators and everything should be fine. I even removed the optical drive and disabled unused chipset/bios features to gain some additional power. Could anyone please help me with this or share some ideas?

here are my spec:
CPU: E6300, 2M L2, 266MHz FSB stock (currently clocked to 300 with stock voltages), Rated FSB 1200MHz
MB: MSI G31TM-P35
RAM: Kingston KVR800D2N6/2G
Kingston KVR800D2N5/1G in Symetric Dual Channel?
currently 5-6-6-18 450MHz (900MHz) - I at least changed the divider to 2:3 since I can no longer
achieve higher CPU clocks
GPU: BFG GeForce 9800GTX+ OC (Overclocked by BFG - no hustle from my side)
core: 760MHz
memory: 1125
shader: 1890
2x 6pin additional power supply
PSU: Eurocase 450W
CPU cooler: aftermarked - Arctic Cooling Alpine 11 Pro
HDD: SAMSUNG HD502HJ (500GB, 7200 RPM, 16MB cache, SATA II)

 

[jitpublisher]

Just because the PSU is supplying enough total watts, does not mean that it is supplying enough power where it is needed. You need to be concerned about the number of amps your PSU is supplying on the 12 volt rails.
The specs on your PSU show a max output of 22 amps on the 12 volt rails if is the standard version, and only 21 amps if it is the SX version. But, if everything was running okay before, I would hesitate to blame all of the problems on your PSU, but instead look to what you have recently changed.

Your new memory is likely the problem, just because it is rated at a faster rate, does not always 100% mean it is better than what you had.
I am not certain of what your original memory configuration was, but you are showing you have 2 different sticks installed right now, a 1 gig and 2 gig? This will not work in dual channel mode, and is a mismatched set. This is likely your problem.

 

[thefuryx]

It is a miss matched set but every program i tried shows me it actualy IS a dual channel and according what I read on various internet pages modern chipsets are capable of this kind of a dual channel except one little detail... its supposed to be asymetric dual channel not symetric