New system freezes when physics happen

[Thalo]

I don't know how much better to phrase the title

I've searched the web and looked through many threads, including in this forum, from people having issues with freezes, but nothing has helped thus far. Wondering if someone can help.

Mostly new system (except where specified):
600W PSU (6 months old)
eVGA GeForce 560 Ti (6 months old) running latest GeForce drivers
Asus P8Z68-V updated drivers
i5-2500K
8 Gigs DDR3 RAM
Main hard drive is 1TB Seagate SATA3 7200RPM
Windows 7 fully updated

Computer runs flawlessly in Windows. Haven't had a single BSOD, crash, anything. No issues watching videos either.

Passed Intel's CPU stress test. The hottest the CPU got was around 85 degrees C (100% load for like 10 minutes).

The problem seems to be in games whenever the CPU does physics. I ran 3dmark11 and it again performs the GPU tests flawlessly, but when it gets to the CPU physics test it freezes up. Full freeze of video/keyboard/mouse/windows, only way out is a hard reboot. I tested a game and loaded up Bioshock 1 (it was at the top of my Steam list and I'd bought it cheap a while back but never played it, thought I'd see if it can handle some 2005 graphics on full) and again it performed flawlessly up until one point, where I believe CPU physics are being used again (once Sub emerges at the beginning and you watch the zombie thing attack the guy and fling his body aside--right at that point when the body is flung the freeze happens. I tried running the game again and the freeze again happened at the exact same point. Sound freezes too, of course.

Any suggestions?

 

[Thalo]

Update: I went into nVidia control panel and for PhysX toggled it to use GPU only, not CPU. I can now complete a full 3DMark Vantage (even the physics test), however still have the issue with 3DMark11 and Bioshock.

Could PSU have anything to do with it? I know it's a bit low, but I have no plans for SLI and when I bought it the store clerk used some kind of calculator to determine that for my system (3 HDDs, DVD-RW, 3 case fans, 560Ti card) the 600W was more than sufficient. It's a Zalman and it says that it's "80 Plus Bronze Rated".

The computer also does something weird on start up sometimes, not a show-stopper, but I'm wondering if it is in fact a sign of an insufficient PSU: On cold boot or re-boot the computer starts up then it shuts off. I wait 2 seconds and it starts up again and everything is hunky-dory. Just thought that was weird.

Maybe the PSU is another problem entirely, but could it be related to the freezing or is there something else going on?

 

[Thalo]

Running Memtest-86. It freezes/crashes every time, usually at the "Block move" test. This time it reboots the system automatically after 30 seconds or so. I ran an older version of Memtest too and it came back with "Unexpected Interrupt - Halting CPU0". I would think that if there were a problem with the memory then it should at least run the memtest and tell me there are errors. I'm thinking more and more it's a CPU or mobo issue.

 

[Dark Comet]

I'm sure 85C is far too hot for that processor. My guess is the max operating temperature of that CPU would be under 70C or around it. Maybe the fans not installed correctly?

 

[Petrofsky]

I'm sure 85C is far too hot for that processor. My guess is the max operating temperature of that CPU would be under 70C or around it. Maybe the fans not installed correctly?

Tcase is 72.6 C.

 

[joe_momma]

The Problem is your cpu, not the graphics card.
I would be willing to bet you have a quad core cpu.
It seems that many motherboard makers are having
difficulty with physics threading on quadcore cpu's.
This problem does not exist on dual core cpu's.