Originally Posted by Russel
The difference between the two versions of the RAM is all about heat dissipation. If you are planning to overclock your computer, or intend to run it under an extensive load over extended periods of time, you may want to opt for the TWIN2X4096-8500C5DF
(the one with the fancy heat sink and fan.) You may want to consider Newegg, the pricing is a little better.
TWIN2X4096-8500C5 at Newegg
TWIN2X4096-8500C5DF at Newegg
As for a quad core CPU recommendation, without knowing what you are planning to use your computer for, I would suggest an AMD Phenom II X4 955 Black Edition Deneb 3.2GHz
. Good performance at a reasonable price.
more specifically if you're planning to overclock your RAM get the second one, it even comes with the $25 Corsair memory module fans IIRC, if it was an AMD build I would say go for the second one, AMD cpus can actually use the extra speed, while with the Intel chips you are usually FSB bound if you want to run a 1:1 ratio with your FSB/memory, a 400MHz FSB is perfect for the first set of RAM and won't run them that hot because they'll be running at stock speeds (800MHz)...
in other words, get the first set, they're all you need with that Intel setup and you won't notice any difference at all even if you overclock the RAM since your max motherboard FSB overclocked is 1600MHz, which would be pretty amazing to get considering it would be double the rated FSB for that chip...