I've had good luck using the 4:5 CPU/DRAM ratio on my BG7. The 3:4 ratio, on the other hand, gives me serious problems.
MeCalvin - I've tried a 256MB stick of Mushkin PC3200 and am currently using a 512MB stick of Corsair PC3200. With both sticks, I had the same issue with the 3:4 ratio being unstable.
Right now, I'm running my BG7 and Corsair PC3200 at 140FSB, 4:5 ratio, Dram H/W Strap at HIGH, Default Vcore and 2.6Vmem. I think my memory timings are at SPD. Sandra 2002 memory benchmark is roughly 2700/2600.
I had an Abit BD7II before this BG7. I RMA'd it because voltage readings were all wacky, even after tweaking the POTs on my Antec PSU. Although I couldn't clock it super high, I could run the 3:4 ratio on it, and it would nly be stable when the DRAM H/W Strap setting was at HIGH. I've emailed ABIT support asking them to release a BG7 Bios that has the High DRAM H/W Strap setting available for the 3:4 ratio. No word from them yet after a week or so.
If anyone is familiar with Bios Modding utilities, any work on enabling this feature would be awesome.
Again, I don't know if my board and possibly MeCalvin's board are from the same batch, which may have issues with the 3:4 ratio. I got mine from Newegg in mid June. Right now I'm happy with the settings I'm using. I can't push it much more until it starts to cool down outside, since I have no air conditioning in my apartment. On hot 90F+ days my CPU temp under heavy load is roughly 62C.
Anyway, long post...thanks to everyone contributing to this thread...keep the posts coming!