Okay I had to learn this a long time ago
I kinda of forgot alot (just needed to pass test LOL)
really what it comes down to is the lower the CL
the faster the ram
if your going to get heavily into OCing you need to know
and this best thing I can do is refer you to Wiki
http://en.wikipedia.org/wiki/Memory_timings
really I cant explain it better than them
they are the same timings just expressed differently
the first number is cas latency
(time to address a bank in nanoseconds? could be wrong)
really just know that the lower the CL the better
but dont get too crazy about it unless you plan to set overclocking records
the faster the ram in mhz (frequency) than the higher the CL normally
for examply the old DDR PC 2100 was CL 2
while my ddr2-800 is at CL5 which is on the lower side for 800mhz ram
but your ram at CL8 is actually pretty low for that speed
there is really alot of detail to it
but I looked at your ram in build
it is 8-8-8-24 CL8
now if you use a CL9 for the other dimms
all the ram will run at the speed of slowest stick
try to match up the timings
but going from CL8 to CL9 for example
really will never make any difference in real world scenarios
unless you are going for benchmark records and Overclocking titles
it doesnt make a difference
if you do want to heavily OC then read that wiki link
changing timings can be crucial in good overclocks