I am wondering if there are some things to do to upgrade my HP a1640n to get a few more years out of it or just get a new computer. I upgraded to 4gb of memory so far. I do understand that I can put in up to the Intel E6700 on the stock motherboard. How much difference would that make? Should I upgrade the motherboard? Is it all cost effective for a few more years? Trying to keep costs down too.