Win7 64bit | DumpFile | 16GB Ram

Ok installed a new heatsink! Temps are within norms now.

Idle 24c | Load 58c max during a burn test with Prime95. Feeling good I got o play BF3. Play for about 20 mins and the PC reboots again.

So its not the temp/heatsink of the CPU. Any other ideas? I could run in singlefire and see if that makes a diff.

You may test your graphic card cooling with FurMark.

pominator said:

You may test your graphic card cooling with FurMark.

tested with Furmark with default (unforced) fanspeed on the GPU. normally when I play games I pump both cards up to 50% for lower and 55% for upper to keep them around 60c (I know GPUs can get hotter but I want them in range even if I kill my fans).

No reboot when running Furmark in crossfire.

Maybe I should run FurMark and Prime95 at the same time stress the CPU and the GPU out?

Im thinking PSU you guys?

A bit more information, I would start over and load optimized default in the bios, then test in order : Ram, CPU, GPU, Hard disk, and eventually power supply if you have a tool or a spare power supply.

Ill load it back tonight.

To test the RAM, use memtest86+. Boot using ultimate boot cd or a bootable ISO/CD from memtest86+ website. Ensure you have latest version. Let the test run for 5 pass, at least. More is better, 5 is usually enough though.
-> If their is error, probably bad memory or bad auto setting in bios.

Ill run the newest version, I think I have it but Ill check their site and report back

To test CPU, use Prime95 latest version in Windows. Use the In-Place Large FFTs test, run it for 8 hours and it will be enough. Monitor temp with RealTemp to ensure it won't go higher than ~70c.
-> If their is error, probably bad CPU or still bad cooling.

Did not feel comfortable running prime95 that long until I got the heatsink Ill try running it that long and see what happens

To test the GPU, as you have a crossfire system, I would finally start by removing one graphic card and to test battlefield 3 with one card only, lower the setting to a playable framerate and play a lot, ~8 hours. If the system is stable that way, remove the current card and install the other one alone, and do the same test. If the system isn't working with 1 card in particular, that card is probably faulty. If the system is stable with both card when used alone in the system, it's probably a driver issue. Try to update the driver. If it dosn't solve the problem, if you can, do a complete format and reinstall the latest driver and try again with crossfire setup. It may also be a problem with your motherboard bios who aren't supporting crossfire properly and a bios update may resolve the problem, if one is available. Before upgrading bios, assuming that your system is stable with one graphic card only, remove one graphic card to run a single GPU setup then do the update according to the manufacturer instruction. Hopefully using a flash drive and the EzFlash bios utility.

Both cards have a double lifetime warranty, so if this is the case ill RMA it. I feel I may be stressing the cards by running eyefinity all the time but the FPS seems decent ~55fps so I dont think Im killing them under load.

To test hard disk, boot using the latest ultimate boot cd disk and do a complete hitachi drive fitness test. One test is enough. It probably won't have any error but the test is easy and quick to do. If you have multiple drive do the test on every drive.

I have a shitty WD Green drive until the price of SSD's drop. I wondered if the rates were killing it, but I doubt it.

To test the power supply, the best test is to use another know to work, and powerfull enough (600 watts is more than enough) power supply. If you don't have one on hand, you can still use a power supply tester, something like this :

Antec.com - Product: Digital PC Power Tester

I have a tester I use at work. I know how they work, someone has suggested that since my PSU is dual rails maybe I was overloading one rail. But I dont think I am.

But it will only detect basic problem.

Yeah tell me about it... I use it at work. basic as in boolean on or off basic.

If you can do all those test and don't find any problem, disconnect other device if you can in the case, like DVD drive, unnecessary hard disk, extension card, etc. Also ensure that every cable are well connected. Another test could be to install a big fan pointing toward the inside of the case, if the problem stop, install additional RAM cooling and chipset cooling. I'm pretty sure you'll find the problem before this step though.

No DVD, I mount over the network DVD drive.
No extra drives.
However I have a shit ton of frills. (Techno LEDancer, NZXT Sentury, 6 Fans, Cold Cathode, Killer Nic. All could be factors.)

Whats a good temp to have ram at?

Also, I have found another thread with a problem similar to yours. It may be your thread though. If not, keep an eye on it you may have good solution there too.

Ill check it out thanks, Im really baffled by this I thought it was temps for sure.

Battlefield 3 Crash Issues. Need help determining if its my CPU or GPU - ATI - Graphic-Displays

Good luck with this.

Ok; Im back! Unfortunately I am still having the same issue.

I have been running some new tests recently here are the results:

No longer testing with BF3, running Prime95 for under 10 mins gives the same result on a fresh boot.
I have stripped the PC down to narrow down anything else that may be causing it running single GPU's at a time; alternating them made no difference.
PSU Checks out all clear with tester.
New heatsink added temps under 100% load for 1Hr 40Mins are 58ish
I have been testing the ram in sets (old and new) even though they are the same model and series.

Tested stock settings (DRAM) Old ram would cause reboot at 10 min mark. New ram ran forever.
Tested with 1.55V Old ram ran for 1hr 40min then I stopped the test (didnt bother testing new ram since it passed the previous test)
Put both ram in Prime95'ed it and after about 15 mins rebooted.

I mounted/pasted the CPU Properly.

So now Im lost from my results I clearly see its the old (first set) I bought as when its in the system it fails; however when I lower the voltage on it they wont crash, but when adding the new set to it I get a crash. I ran a Memtest86+ on the old ram over 18 hours and didnt get a single error. Windows works fine, its only when the PC is under full load; counterstrike and shit is fine as weel just BF3 or Prime95.

Download and install CPU-Z and Upload screenshots of the CPU, Mainboard, Memory, and SPD tabs. In the SPD tab, upload an image of each slot.

Also, go into your BIOS and post all Voltages (CPU, RAM, NB, IMC, etc.) and all RAM settings (timings, frequency, etc.)

Thanks to Dave76 for help learning RAM Stability