Mushkin 4GB XP2-8500 @ Techgage
 

Mushkin is the only memory company right now to offer
4GB extreme
performance kits, with their top-end offering on our test bench today.
Despite the fact that it already has high stock speeds, we were
surprised to find out that it still had a lot of overclocking headroom.

http://techgage.com/article/mushkin_4gb_xp2-8500/