Difference between CAS-2 and CAS-3?

[Bobstopper]

Whats the difference between these two memory ratings?

 

[Jumpem]

It's the latency(in milliseconds?) of the memory. Cas-2 is faster than Cas-3, and will yield slight improvements in performance. I'm sure that someone else will have a more technical answer for you.

 

[interchange]

Actually, it refers to the number of clock cycles it will spend before assuming that the column address of RAM in your modules will actually arrive. Essentially, most CAS-3 modules will do CAS-2 at or often beyond their rated clock speed. So, if you have the option, buy good CAS-3 RAM and run it at CAS-2.

 

[Rigoletto]

GOD! Doesn't anybody know how to use the search facility?
BTW CAS 2 does not give 50% faster speed over CAS 3. Just thought I'd tell you that...

 

[pm]

Good answer, interchange, although it's worth noting that if you run CAS3 memory at CAS2, you are effectively overclocking it (ie. running it faster than spec.). Yes, as you said, it usually works but it's worth mentioning nonetheless.

It's also worth mentioning that running PC133 memory at CAS2 results in a 1-5% performance improvement over running it at CAS3 (the variation depends on application - applications that mostly run in the cache will see little to no improvement, applications that swap in and out of memory a lot will see more).

 

[hans007]

its like 3% faster, since a column access is well 50% faster, but that doesnt mean anything since most of the time its doing reads which is why its only like 3% different. I've got pc100 cas2, it runs at 140mhz at cas2. So usually you can go on the cheap, its not worth the premium especially with the disparity there is now.