Can my new 260 GTX card effect CPU core voltage?
 

Question: Is it possible my CPU's core voltage could have dropped after adding a 260 GTX video card?

Background: I recently bought a EVGA 260 GTX and after installing it immediately started experiencing crashes (i.e. random system reboots) while playing games. I've tracked it down to the CPU, and if I lower the overclock I don't have any problems. Nothing has changed except the video card and my system was rock solid stable before it was installed. Looking at the core voltage in CPU-z it seems to be lower than I remember it with my previous card. Could adding the 260 GTX cause voltage to the CPU core to decrease? How accurate it that core voltage anyway? The difference between my motherboard bios setting voltage and CPU-Z is 0.04 volts idle and 0.07 under load. When I'm looking at max voltage to the CPU, should I go by motherboard or CPU-z? Any comments are appreciated.

System: Gigabyte P35-DSR3 motherboard, Intel E8400 @ 3.8 GHz, 4GB Corsair memory, EVGA 260 GTX Superclocked, Corsair 520HX power supply.

Re: Can my new 260 GTX card effect CPU core voltage?
 

It's possible that your PSU could be giving out. Is that Corsair a single or dual 12v rail model? If it's a dual, then I would say it's very possible.

Re: Can my new 260 GTX card effect CPU core voltage?
 

Actually it is a triple 12V 18A rail. This is also the first time I used the second PCIE 6 pin connector. The power supply is certified for SLI.

Re: Can my new 260 GTX card effect CPU core voltage?
 

I have a similar system:

E6300 @ 3.1
GA-965P-DS3 (1.0)
260 FTW Edition
Corsair HX520

Haven't had any problems

Re: Can my new 260 GTX card effect CPU core voltage?
 

It sounds as if it due to the current draw as if they are sharing the same 12v rail

Re: Can my new 260 GTX card effect CPU core voltage?
 

doesn't matter that PSU was certified for SLI few years ago, when video cards didn't require that much juice.

Re: Can my new 260 GTX card effect CPU core voltage?
 

Check the max 'shared' load in the 12V rails. Usually it's lower than the sum of the single rails.

Re: Can my new 260 GTX card effect CPU core voltage?
 

Exactly, my Thermaltake 700 has four 18 amp rails, but at 100% they will only put out a total of 47A combined.

Re: Can my new 260 GTX card effect CPU core voltage?
 

Yes. When I had a 2900XT I lost about 100mhz off my CPU overclock due to the extra power it was using over my 8800GTS. I was using a 720w Enermax PSU.