Big diff between PC4200 CAS2.5 and CAS3?

[DMC8260]

Is there a big difference between having a pair of PC4200 ram that runs CAS2.5 and a pair of PC4200 that runs CAS3?????
Or is it just by a bit???

[hepp]

Hardly noticeable difference between 2,5-4-4-8 and 3-4-4-8.

If you can reduce tRP or even tRCD from 4 to 3( i.e. 2,5-4-3-8 or 2,5-3-3-8) that will be a noticable improvement but at PC4200 speeds that is most likely not possible.

Br
hepp

[hepp]

Speed_mechanic2 made a nice comparison in this thread (http://www.ocforums.com/showthread.php?s=&threadid=258304)

Here you can see how much difference each change makes.
Because he used BH5 memory he wes not able to test CAS=3 but you can see how small the difference is between 2-3-3-7 and 2,5-3-3-7, expect that the difference between 2,5-4-4-8 and 3-4-4-8 is smaller still.

Flapperhead wrote in the thread lower timings, same bandwidth-doesnt make sense! (http://www.ocforums.com/showthread.php?s=&threadid=257851) that:
i've gotten the memory up to 290 @ 3-4-4-8. just tonite i figured what the heck, lets see how far i can drop the timings . well lo and behold i can run the memory at 2.5-4-4-6. in my book that is a decent drop, but my bandwidth numbers stay the same as with 3-4-4-8

Bandwidth does not tell the whole story but if you read the whole thread you might be able to come to a conclusion.

Br
hepp