my question is i currently have the core 2 duo E6420 , and my other specs are : gpu ati radeon hd 4870 RAM 4 gig psu Corsair HX 520W motherboard ASUS P5LP-LE (does not support quad core) if i was to upgrade the cpu to the core 2 duo E8400 will i se a big difference?
A reasonable one, but if your board doesn't support quads, it won't support the E8400 either, at least not without a BIOS flash. You're best off getting a new board and a Quad core CPU.
Not one that's good enough to be worth doing. Save up until you can replace the board as well as the CPU.
yh i have the money but doing all that is like buying a whole new computer , i think ill just wait few months and just get a new computer