how to trade off RAM MHz vs CAS?

[OS]

How do you go about deciding what's good? Like my ram will run at 133 cas 2 or 150 cas 2.5

 

[OS]

well, my limited testing in Q3 seems to say 150 cas 2.5 is faster than 133 cas 2

 

[Lord Evermore]

Lower latency with DDR of only half a cycle only provides about a 1 to 2 percent performance increase at best. Most of the time, higher bandwidth will provide a better performance increase. However if your uses aren't actually straining the bandwidth, then it may not make any difference at all. Some games might like the higher bandwidth better (especially if you're increasing the CPU frontside bus to match it), while other games and applications may be affected more by the processor speed.

Really, the best advice is to try it for yourself. If you've already got memory that you know will run at those speeds, test it. If you're just looking for which type of memory to get, get the best that you can afford without having to wonder if you're throwing your money away.