VTEC

Set the DRAM Drive Strength from 9-15 for 4 sticks of RAM. I have mine set around 10 or 11.

Try a DRAM Drive Strength of 10-15. 4 sticks of RAM need a Drive Strength in that range to run stable on the Expert. I have mine at either 10 or 11, I'm not at home to check for sure.

Assassin, we have eerily similar computers. I also have the same problem, anything above CAS 2 will post but not let me load XP. I'm not at home at the moment so I can't test this, but I'm pretty sure I can't load XP even at stock DDR400 speeds at CAS 2.5 or higher, yet at CAS 2 everything's fine. My problem is that with 4 sticks of TCC5, I can't overclock as well as 2 sticks and thus I'm stuck with slower speeds and thus slower cpu speed.

My DFI Expert won't boot. 4 LED's light up. I had this exact same thing happen to my last Expert almost exactly 12 months ago. Back then, and again this evening, I got an electric shock when hitting the power button on my PC case. After that, neither board would get past 4 LED's. The first time this happened I transported every piece of hardware from the old, non-functioning Expert board to the new Expert without problems. The board ran great all year, except now I'm stuck with two non-functioning boards. I never got the old one fixed although I still have it. I've tried the work arounds including following the proper CMOS reset procedure. No dice. I'm under the assumption now that both boards have a corrupted BIOS, is this plausible? I suppose I need to send them to DFI to get reset? Any idea how long this takes? I'm stunned...

SLI works great for me. In some cases nearly doubling the performance over a single card. Games do still bottleneck with the cpu in some instances though...

Did you enable SLI in the BIOS?

What DRAM Drive Strength setting are you using?

I was able to pass memtest but games were crashing until I changed the DRAM Drive Strength to 11. Since then, it's been smooth sailing. Except Oblivion, which seems to crash to desktop everyonce in awhile when the game is loading. For whatever reason, I get the impression it's the software though...

BF2 also needs 2 Gig's to run smoothly on the highest settings at 1600x1200. I tried DRAM 10 and 11 and both times it failed at 1T DDR400. 2T DDR400 is rock solid stable at DRAM 11. I can't tell you how nice it is to have a 100% reliable computer again. Still, it'd be great to get to 1T with this board since others can, my last Expert included... I might try DRAM 13 and 15 later at 1T.

I think I solved it. DRAM Drive Strength at 11 allows me to boot at DDR400 2T. It ran 3DMark06 without issue. I'll continue testing but so far so good. Previously, I'd only tried 1-7 for Drive Strength... live and learn.

Just got an Enermax Noisetaker II 600W PSU with the 8pin power connector. It's still unstable at DDR400 with 4 sticks at 1T. It won't even load Windows at 2T. It does pass one pass of memtest at DDR400 1T 2-2-2-5 but overnight will show errors. Games crash quickly at that setting. Even DDR333 isn't rock solid stable at 2T. It's still crashing occasionally in games. And the review I linked to at HardOCP states they weren't able to get the Expert stable with 4 sticks at DDR400. So I need 2 x 1 Gig?

What voltage are you running them at?

Bump. I'm having the same problem, although I hear my PSU isn't enough, I have identical symptoms as the guy above and this is my second Expert board. With the same hardware, my first Expert ran the same 4x512MB sticks at DDR400 1T with ease. I'm considering a new psu, 520W OCZ or 600W OCZ?

Weird, I have the exact same problem on my first Expert board. It died on a Friday afternoon too. :S 4 LED's and no boot. Fans come on, but no image on monitor. Oddly enough, I also have an Antec 480W psu, though mine's the NeoPower. I bought another Expert board and transfered everything over, and everything works. The first one died rather unexpectedly, I powered down the computer normally the night before, and when I turned it on the next day I got a large static shock when hitting the case's power on button. Anyway, I have no idea if that caused it, but the board appears dead. I still have the dead one and have been trying to get it going, but no luck. It's 2 months old, do I contact DFI for RMA? Can I still RMA it?

I have the stock BIOS, I'll find out which that is. By the way, this article at HardOCP states the Expert is unstable at DDR400 with 4 sticks of RAM. Is this right? My last Expert board was rocksolid stable at those settings, 1T as well. This one won't even boot at 2T DDR400 for some reason, but will at 1T (except it's unstable). Would the power supply (NeoPower 480W) potentially stop the system from running DDR400? It's been stable at DDR333 today for a couple hours in games that crashed within a few minutes at DDR400.