Depends on the power supply and motherboard, if your psu is 450w and rated 80 plus bronze or higher, then absolutely. If its not rated well, lets say 50% or 55% which is common for lower quality psu's, then your looking at a 450w supply that will deliver 200 watts, then since its an fx chip and you need a gpu, I would say you'd need to upgrade your psu and your cpu.
But also agree, don't I mean don't upgrade to a 6100, go 6300 or no 6000 series at all. the 6300 is a huge step up over the 6100.