I've been having random reboot problems and I believe it's the ram. I contacted OCZ (I use OCZ3P16002GK DDR3 ram) and they are saying it's difficult to get this ram working right on this motherboard. Timing issues I suppose. IT reboots even at 1333.
I've swapped out motherboards, power supplies (OCZ 600w) and things are running cool enough. OCZ's comment leads me to think I may as well change ram to something better for this board if I can.
I've heard good and bad about different brands. Of course, if someone has the same mother board and can give me what brand DDR3 they are successfully using, that'd be great.
I am very pleased with the speed and stability of the new 8GBs of DDR3 I got for my DX48BT2. I got two of these: Crucial BL2KIT25664BA1336 4GB kit (2GBx2) Ballistix DDR3-1333 PC3-10600 NON-ECC 1.8V 6-6-6-20 240-pin DIMM Gaming Memory. So I thought I would share because I had to read a lot of posts to try to figure out which memory could be the fastest yet stable.
I'm running the memory at DDR3-1333 ; and had to manually change the timings to: 6-6-6-16 / 49-3-7-4-4 (RFC-RRD-WR-WTR-RTP) as Everest reported.
I also have a Core 2 Extreme CPU QX9770 overclocked to 4.00 Ghz on this system running Windows 7 x64.
I also had to downgrade the BIOS version from the latest which had hanging problems to version 1997 (04/28/2009).