I am currently running 2 gigs on vista 1 gb stick that is pc2-4200 and one that is pc2-5300would there be an increase in speed if i upgraded to a dual channel pc5300 667 mhz kit? I still have use for the old ram that will go into a different computer that has 512 mb now, but would i notice a increase in speed? Do i lose dual channel by having 2 seperate sticks with different speeds? according to cpu-z the ram is currently running at 266 mhz sigh. I do not plan on overclocking, I am not a fan of overclocking.