Q: My MoBo's chipset is a AMD 690G. It currently has a Amd 4800 X2. I was wanting to see if a AMD 6400 X2 would fit.. Yeah, my cpu socket type is AM2. http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_14603_14764,00.html
A: No problem what so ever,I went from a AMD Sempron AM2 socket to a Athlon 64X2 6000+ and then overclocked a little to 6800+ and it works fine.You should have no problems.