Is CAS 9 1333 better than CAS 7 1066 ?

If equally priced, I would go with the DDR3 1333.

To the average user, you'll see little difference between those two RAMs at different timings. Also, you can always down clock the DDR3 1333 to DDR3 1066 Cas7 timings.

I would agree that the CAS7 is a small bit faster -- figure going from 1066 to 1333 is a 25% increase in speed but moving from a 7 to a 9 latency is a 28% increase, so you are getting a 28% increase in the amount of cycles it takes to process a request but with only a 25% increase in the number of cycles processed per second.

Though in real world performance the difference would be unnoticeable !! (But on the other hand the 1333Mhz. memory would probably be able to OC and remain stable for higher Oc settings than the 1066 Mhz. memory does !)

Hi.

I'd say that 1066 CL7 is much faster that 1333 CL9. Why u don't check the Ripjaws 4GB kit 1600 that are CL7 for only $102.99

You are all wrong.
Tight timings means 2 cents performances boost and 200 bucks troubles (stability issues).
DDR3-1333 running with 7-7-7-20 is about 1-2% faster than DDR3-1333 running with 9-9-9-24.
DDR3-1333 (by default CAS = 9) is 4-6% faster than DDR3-1066 (by default CAS = 7).

cheers