Lol... Yeah it can be a bit quirkly like that... It reads my CPU as running at 127 degrees in win7 x64 (in bios it reads around 30), but each core is between 20 and 30... On my old 32 bit XP system it was spot on at around 35/40... Go figure
I haven't actually tried speedfan on my new motherboard, but on my old foxconn 590 SLI board it was pretty much useless. Didn't detect Northbridge at all, CPU would read at 60 degrees no matter what I did, I apparently didn't have a GPU etc...
I should be getting my new CPU later this week, the 3.4Ghz AMD quad. I'll probably have that running at about 4Ghz (don't want to push it too far lol) once I slap the liquid cooling system on it
As for saving up for a new GPU? I'm not saving, I'm waiting... I want to see what the nvidia DX11 cards have to offer when they come out later this spring