I have an MSI 760GM-E51 motherboard, and I was thinking to buy a new CPU for it: AMD Phenom II X4 850
The question is, then I look in spec for the motherboard, there is writen "FSB/BCLK/Hyper Transport Bus up to 2.6GHz", and then I look at new AM3+ motherboards there is writen "up to 5.2GHz", so how big is this diference, if I want to buy this new CPU, should I buy also an new MB with higher FSB speed ? Is this MB ok?
Are you sure you're not confusing GHZ with G/Texels? At any rate, the 2.6GHZ bus rate is sending 5.2GT/s and is sometimes referred to as GHZ. So worry not. Your 2.6GHZ is indeed performing at 5.2GHZ or GT/s
And the controller sends 2 data packets per clock cycle, effectively doubling the rate to 5.2GHZ. That's why it is confusing sometimes trying to compare speeds. But you have the fastest current AMD HT speed.