Well tonight I found it's definitely an issue with my RAM.

With FSB of 550 I was able to get into Windows and run programs without much stability testing, but got further than at FSB 400 (then I had to pull my 3870 X2, as I sold it )


The main difference, at 550 FSB the RAM was at 1100 MHz and it was fine. At 500 FSB the RAM was at 1200 MHz and it was fine. At 400 FSB the RAM was at 1600 MHz with very relaxed timings and generous voltages and it would BSOD in a matter of minutes after getting into Windows.

550 FSB was a bit tricky, but once I played with NB volts and some GTLs it booted into Windows, which shows that it's doable on my board, only with the RAM at 1:1 6-6-6

Funny enough, at 500 FSB 1200MHz DDR3 6-6-6 PL9, the bandwidth and latency in Everest was very similar to what I was getting out of my DDR2 at 1133 5-5-5 PL7 on FSB of 478

So the board is capable. Now to find some sticks that can keep up.