All right, I guess its time for a little update. I've spent the last two weeks playing with this motherboard and it by far the most rock stable AM2 board I've tested. Memory overclocks were far too impressive through this motherboard and I was able to overclock my Micron D9 based modules way over the limit. I've tested two different processors on this motherboard and both overclocked impressively well.
Test Setup:
AMD Athlon 3000+ "Orleans"
AMD Athlon X2 3800+ "Windsor"
DFI LP UT NF590 SLI-M2R/G (BIOS 829)
OCZ PC8000 Titanium Alpha VX2 2x1GB (Micron D9GMH)
ATI X800XL 512MB
FSP Epsilon 700W
Corsair Nautilus500================
CPU Overclocking================
First off, here's a screenshot of my little Athlon 3000+ "Orleans" running Prime at 3GHz for over 8 hours:
AMD Athlon 3000+ "Orleans" @ 3010MHz | 334.5HTT | 1.616Vcore | 501MHz MEM | 46ºC LOAD | 8 hrs 33 mins Single Prime
As you can see in the screenshot, Vcore seems to be pretty darn stable but it showed little fluctuation during early stages. SpeedFan recorded only about 0.016V fluctuation at most. This was mainly thanks to the digital PWM! Next, we have some dual core OC action! Btw, Smart Guardian over-reports the CPU temperature by about 12ºC. So we will rely on Core Temp for more accurate CPU temperature readings.
AMD Athlon X2 3800+ "Windsor" @ 2706MHz | 270.7HTT | 1.328Vcore | 451MHz MEM | 6 hrs 41 mins Dual Prime
My new X2 3800+ overclocked pretty well at default Vcore but only to fail after passing over 6 hrs in Prime. Bumping the Vcore a little will definitely help for 24/7 usage. Besides that, the PWM temperature raised significantly when running a dual core processor. So make sure the PWM heatsink is well cooled.
AMD Athlon X2 3800+ "Windsor" @ 2810MHz | 281.7HTT | 1.504Vcore | 468MHz MEM | 55ºC LOAD | 24 hrs 21 mins Dual Prime *CPU Cooled by SI-128 + SilverStone FM122 (air-cooled)
Here, we cooled the CPU using a Thermalright SI-128 paired with SilverStone FM122 100+cfm fan and left it priming for over 24 hours. As you can see, our X2 runs 100% stable at 2.8GHz. However, it requires 1.5v which causes the CPU to generate a lot of heat. You can also consider this as a 24 hours burn-in for the system.
AMD Athlon X2 3800+ "Windsor" @ 2904MHz | 290.4HTT | 1.66Vcore | 484MHz MEM | 63ºC LOAD | 12 hrs 46 mins Dual Prime 
I switched back to Corsair Nautilus500 watercooling and headed for maximum stable overclocks for the X2. Although I was able to boot up at 3GHz, it was not stable. So, at the moment, 2.9GHz seems to be the max stable for my X2. It required quite a lot of Vcore and 1.6V will allow the CPU for 24/7 usage. In the screenshot, we gave it 1.66V and left it priming for over 12 hours. Temperatures were getting too hot, even for our water cooler. Next, we'll hunt for the maximum memory speed.
================
Memory Overclocking================
AMD Athlon 3000+ "Orleans" @ 3101.8MHz | 344.6HTT | 1.69Vcore | 620.4MHz CL5-6-6-15 MEM | 2.8VDIMM | Super PI 1M
At 620MHz, DDR-1240, or PC-9920 was pretty impressive and was a little stable to complete the Super PI 1M run. Now, let's go for max suicide clock!
AMD Athlon 3000+ "Orleans" @ 3207.2MHz | 356.4HTT | 1.69Vcore | 641.5MHz CL5-6-6-15 MEM | 2.8VDIMM | SuIcIdE
At 641MHz, DDR-1282, or PC-10256 is very impressive! I wished the system was a bit more stable. Running any program will instantly crash the system. Heh.. maybe I need a better pair of RAMs.
================
HTT Overclocking================
AMD Athlon X2 3800+ "Windsor" @ 1873.6MHz | 374.7HTT | 1.50Vcore | 375MHz MEM
The maximum bootable HTT through BIOS is 350HTT and requires x3 HTT multiplier to do so. Increasing motherboard voltages doesn't seem to help improve HTT overclocking, at least with BIOS 829. Then, we booted into Windows and ClockGen-end our way to 375HTT. ClockGen will work over 400HTT but the motherboard ignores ClockGen setting when going over 375HTT. Besides that, I also noticed "HTT drop" when setting to 375HTT. After a few mins of Priming, the HTT will start to drop until it reaches 372-371HTT. I've reported this issue to DFI and they are working on it. Frankly, HTT overclocking is not impressive on this motherboard. Almost all of AM2 motherboard I've tested does at least 400HTT easily. Let's hope DFI unlocks the secret behind the SLI-M2R/G motherboard.
*Crossing my fingers*
