hey do any of you wonderful people know about pc components in relation to rendering times?

for instance my setup is a core i7 930 oc'd to 4.0ghz, gtx470 graphics card, 16gb corsair ram, 1tb wd drive
asus p6x58d-e, and lots of fans,
now i originally had 8gb of ram and after installing 16gb i didnt really notice a difference in render times, so im seriously thinking of getting a solid state drive, my theory being the insane read write speeds will help with rendering images, but will that actually happen or is it all down to the CPU??

cheers if ya can help