My 990FX-UD3 wouldn't post over 290. But I had that board before I heard of FSB deadspots, so I never tried it higher. Both the M5A99X-Evo and M5A99FX-Pro I've had would do 300 but were pretty glitchy (Icons popping slowly - freezing) Not Ram related as it was turned down pretty low as well as CPU/NB and HTT to run near stock. I didn't try to go over 300 on those boards so not sure if it would have done it.
Another OCN Member that was having trouble clocking over 4.5Ghz on an 8120 tried turning down the voltage on the DRAM Modules from 1.65 to 1.5v and is now happily running 4.6Ghz with no issues.
- Not sure if they could go higher because that is the limit of their cooling atm.
- Not sure if it is just something to do with the Asus boards either