Looks exactly like the same BIOS/MB error I get aGeoM. Try another Phenom supporting board to see if it boots in that before you think its CPU, that's what I did before but it was wrong. I doubt very much its dead, ICs don't fail like this suddenly
I don't think it's a coincidence that only DFI board is getting this sudden error in high numbers especially because of its RAM problems since the start. C1 is Memory related. My board is the only one getting it for other boards AFAIK and I have a replacement I'm going to check with the same 9850 this week. If it boots fine whilst older MSI board gives C1 Memory initialization error, then its obviously a board problem and not CPU.

And mine is from the earliest released batch of MSI RD790 v1.0. The DFI is much newer though.

Yea I know what you were saying Achim, I'm trying to look for trends. I can't test higher NB because it has separate limits. For instance, 1.3v 2380 max, whether I ran it at 1800CPU or 2900CPU. The word "stable" I guess have different meanings with users. I've tested and can still test 1.2v 2200NB stable with some stability test but that would be lying to myself since I know in general usage that fails stability and there would be no point me misleading others about it.