DFI LP DK 790FXB-M2RSH / ATI Radeon 4800 series problems

[flyinfinni]

I just built a brand new system at home, and have been having some problems, and was hoping to find some advice here. The system is this:
CoolerMaster RC 690 w/6 120mm Case Fans + 1 70mm fan on the back side of the CPU
DFI LP DK 790FXB-M2RSH
AMD Phenom X4 9950 BE + Xigmatec S1283
2x2048 OCZ Fatal1ty PC 8500 DDR2
1 maxtor 500Gb HD (Booting Win 7 RC 1 64-bit)
1 Western Digital Caviar Black 320Gb HD (Booting Win Vista Home Premium 64-bit)
1 LiteOn DVD+/-RW
OCZ ModXstream Pro 700W Modular PSU
ASUS ATI Radeon EAH 4870 DK TOP

The problem I have been having is with the Graphics cards. Every time I run a full screen application or video (even things like Hulu on full screen), the display crashes. This happens with both Win 7 and Win Vista. Sometimes it will give me the "Display adapter has stopped responding and has recovered" (which sometimes it does, and sometimes I have to do a hard reboot) and sometimes it gives me a BSOD, though never for long enough for me to read what it has to say. This is not a problem with the Graphics card itself as I had a Sapphire 4830 that was originally having this problem and after lots of diagnosing and trying to fix it, switched to the 4870 I have now- same problem. I have tried the latest versions of the drivers, I have tried rolling back to earlier versions of the drivers. Temp is not a problem as my case is cool with good airflow, my CPU sits around 38 at idle and haven't seen it go over 50 since I installed the Xigmatec cooler. I haven't seen the GPU go over 60 even at full load. Anyone have any suggestions?

 

[starams5]

Hi

Since this is a new build did you update to a current bios? And how do you have your memory voltage & timing set up in the bios, manual or auto settings.

 

[flyinfinni]

I have not flashed the bios yet, but as far as I could tell the only difference from the BIOS I have to the latest version is compatibility with the Phenom II processors. I am planning on trying it this afternoon anyway. As far as Mem voltage and timing goes- they are set on auto. I did have to set the mem clock to 1066 manually, but I ahve read this is fairly typical with most AMD 1066 compatible boards.

 

[starams5]

The auto settings are fine if you are not having any problems, I'm a strong believer in if its not broke don't fix it, but its time to get in there and see if you can get the board stable. As you may know most if not all 1066 ram is OCed 800 ram. First set the voltage at manufactures spec and test. If you're having problems, manually set the timing and test. Last, if the problem has not been resolved try down clocking your ram gradually if it is currently running at 1066MHz.

 

[flyinfinni]

I've done some pretty extensive ram checks and testing (haven't had a chance to actually mess with the timings and voltages yet, but I'll give it a go later) and it doesn't really seem to be a ram issue. I did drop in my old GeForce 7300 GT and everything ran beautifully, even on full-screen apps which is where I've been having problems.

 

[flyinfinni]

After doing more testing, turns out it was the PCI-e slot. I moved the card to PCI-e slot #2 and was able to crank away everything I tried without a single crash. RMA on the MB is in progress. Hopefully things work well with the next one.