Overclocking advice

[Largo_npc]

My Current system is:
P5N-E SLI
Q6600
Artic Freezer 7
2x1GB 800Mhz DDR2 Patriot
2x2GB 800Mhz exilr
OCZ Stealth 600w PSU
GTX260 896mb

I've tried overclocking. I can get it to 2.61 by increasing the FSB to 1166 (1166/4 = 291.5). It seems to run fine and stable.
I tried increasing the FSB to 1200 (300) and keeping the memory Unlinked and at 800Mhz. The first time I tried it crashed shortly after. Now when I try I just get a blue screen on windows loading saying a Hardware Fault. Then the Bios refuses to keep my OC settings until I reset the CMOS.

I'm quite confused, I would assume that I should get more out of the CPU with these items.

I will be getting the CoolIT Eco A.L.C. CPU Watercooler at some point in the future, I also know I need to replace the exilr memory.
I've looked into upgrading to DDR3 but I can't afford much, so a DDR3 Socket 775 is out of my price range and any other i series socket is too as I can't afford the CPU.
I've also been looking at CL4 Memory to match my Patriot stuff. OCZ Titanium CL4 800Mhz seems to be a decent way to go, but I'm unsure.

I'm basically looking to make my system run a little nicer at as low cost as possible.
I am getting the Gainward GTX460 GLH too though

Any advice would be appreciated. I've just started a job building PCs and they are training me in overclocking, but I find it hard to understand how to work out Voltages, so some pointers there would be good too.

Thanks!

 

[w3bbo]

Sell the P5N-E SLI and get a board that can overclock quad cores. NVidia based chipsets are not the best choice.

In the meantime....have you played with the voltages (namely vcore?) if not set this to 1.45 and see how far you can push the FSB.

 

[mark1522]

I had a similar board P5N32 sli se deluxe.. it was a bugger to overclock even a few clicks on the fsb and wouldnt restart till i removed battery and reset cmos...im not sure if yours is same /similar to mine but mine had a poor overclocking nvidia chipset and was known to be poor..get a different board and o/c it

 

[setter]

Agree with w3bbo 100%, i had a supposed quad friendly evga 680i a1 board, it wouldnt clock my q6600 above 3.0ghz for love nor money, put the same chip in an asus p5q deluxe p45 board, 3.8ghz on air with relative ease. Such a pity as the same 680i board took my crap e6600 to 3.7ghz, first board i learned to overclock on.

 

[Largo_npc]

I had a feeling it was the mobo. I'm going for an Intel based chipset, maybe a gigabyte. I'll see what we have at work.