What is the weak link in my system for OC'ing?

[g-unit1111]

I've attempted to overclock my Intel Core i7-920 to 3.0GHz and beyond. Using a 15x multiplier and 1.20V I've been able to get the CPU to run at 3.0GHz without breaking a sweat. But any attempts to OC beyond that have resulted in BSOD's, OC failures and random error messages. I've had to default and run at 2.8GHz so my system runs stable. Here are the specs:

Case: Corsair Graphite 600T
PSU: Corsair TX750
Motherboard: Asus P6T
CPU: 2.66 GHz Intel Core i7-920
Cooler: Thermalright Silver Arrow
Paste: EVGA Frostbite
RAM: 12GB Corsair Tri-Channel RAM PC 1333MHz timing 8-8-8-20 1.5V
Optical: Plextor B940
Video Card: 2 x EVGA Geforce GTX 550TI 2GB
SSD: Intel 320 120GB
HD: Western Digital Caviar Green 1TB
OS: Windows 7 Home Premium 64-bit

So it's been driving me crazy and I cant seem to figure it out - is it my PSU? Is it my choice of cooler? Do I not have the cooler installed correctly? Do I need to take apart my cooler and re-apply the thermal paste? Do I need to try different thermal paste altogether?

 

[nna2]

hehe, trust me... coolers are meant to cool, thats it they wont affect your overclock
unfortunately, every processor has its limits on where it can overclock, is its blue screening, youve probaly hit that limit

 

[Cygnus x-1]

Why are you using a 15 multiplier? If anything go with the 20x multi, and then decide to turn turbo on or off.

 

[christop]

You haven't hit your limit. I have my I7 running at 4.1ghz but my multi was lowered and my blck is raised to 215 plus My cpu volts are set to 1.32 and 1.3 for northbridge. You might want to read some tutorials. I would try google. Good luck

 

[Cygnus x-1]

Lowering the multi and raising the blck is just going to make an overclock less stable and higher clocks more difficult to achieve.

 

[g-unit1111]

hehe, trust me... coolers are meant to cool, thats it they wont affect your overclock
unfortunately, every processor has its limits on where it can overclock, is its blue screening, youve probaly hit that limit

Well the main thing I'm concerned with is that I was checking the temps on my motherboard - the CPU idles at 40'C where on the SB build I use at work is paired with a dual-fan Cooler Master Hyper 212 and I have that running at 20'C idle. So I'm thinking I have it installed wrong since I know the i7-920 can be OC'd beyond 3.0 GHz. Is that possible?

 

[nna2]

mine idles at 40, and maxes at 70, those are okay temps