I agree that the 8-core AMD FX-8350 is the better upgrade path. You also want to have DDR3 memory that is faster than the DDR2 which is slower.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131795 Motherboard $55
http://support.asus.com/Cpusupport/List.aspx?SLanguage=en&m=M5A78L-M%20LX%20PLUS&p=1&s=24 ASUS CPU Support - Shows support for this CPU/Motherboard Pair which is important as for some max out at 4 and 6 core CPU support, while this one will handle 8-cores.
http://www.newegg.com/Product/Product.aspx?Item=N82E16819113284 CPU $200
Newegg has free shipping on both of these items.
* Just need to add DDR3 RAM and most of the components of your current build can migrate to this build. Also depending on motherboard features you may want to go with a motherboard that supports greater than 8GB Ram, USB3.0, Crossfire etc. But this board I linked is probably the best bargain for AM3+ motherboards that I have seen for features and a quality board that should be trouble free. I was tempted to buy the motherboard a week ago when I saw it this cheap but didnt.
Originally I was going to upgrade to a socket AM3 Phenom II x6 myself about a month ago to upgrade one of my other systems from its Sempron 145 single core and have that system become my primary gaming system since its AM3 socket motherboard running on DDR3 memory supports the Phenom II x6, and my current gaming system is an older AM2+ motherboard that has the AM3 Athlon II x4 620 in it and is slightly bottlenecked by the DDR2 800Mhz RAM when the CPU is best paired with DDR3 RAM, as well as the motherboard only supports 4GB RAM maximum 2GB per slot and the other supports 8GB maximum.
What I found was that the 6 core Phenom's are only available as older stock online and come at a premium. Newegg etc only has the Phenon II x4's and no longer have any 6 core for AM3 socket available. I was thinking of originally just swapping the CPU's between the two motherboards, but the small gain between DDR2 and DDR3 run speed wasnt worth the work and rebuilds of OS etc. But if I tapped into DDR3 memory with a Phenom II x6 plus could have 8GB RAM with 64-bit OS, that was going to be pure performance and worth it for me.
But when I looked around, I saw that for about the same money it was going to cost me for that Phenom II x6, I might as well go with a newer not too expensive good name brand motherboard and FX AM3+ socket CPU that benchmarks better than the Phenom II x6 as well as have the ability to upgrade further down the road vs stuffing a Phenom II x6 into the motherboard I have that supports it and after spending the money not able to upgrade further because the board is running to its maximum supported potential.
I decided to hold off on the upgrade for now with the mindset that if I hold off now, I can get something far better later on for the same money. What i have now is plenty for games I run etc. I dont have any lag with the quadcore and the video card I am using. But when I start to feel that the Motherboard/CPU combo are no longer holding up to the games I play, I will be forced to have to upgrade at that point. With a 4GB RAM Max on this gaming system built in 2009, that Motherboard/CPU/RAM upgrade will be sooner than later.
