For any ram you are considering, do your own homework.
Go to the ram vendor's web site, and access their configurator.
Corsair, Kingston, Patriot, OCZ and others have them.
Their compatibility list is more current than the motherboard vendor's QVL lists which rarely get updated.
Enter your mobo or PC, and get a list of compatible ram sticks.
Here are a few links:http://www.crucial.com/index.aspx http://www.corsair.com/configurator/default.aspx http://kingston.com/ http://conf.ocztechnology.com/index.php?c=1 http://www.patriotmemory.com/configurator/index.jsp
Cpu performance is not very sensitive to ram speeds.
If you look at real application and game benchmarks(vs. synthetic tests),
you will see negligible difference in performance between the slowest DDR2 and the fastest DDR3 ram.
Perhaps 1-2%. Not worth it to me.
Don't pay extra for faster ram or better timings unless you are a maximum overclocker.