Memory timings vs CAS latency

[lex-luther]

My memory (crucial ballistix) can run at 400mhz 4-4-4-12 or 533mhz 5-5-5-15. Is there any advantage to running it with lower CAS latency (4-4-4-12) or does the higher speed always reflect increased performance?

 

[Perp]

Well it's technically 800 and 1066.

The difference is minimal and really comes down to overclocking options. If you can run well over 400mhz fsb then start to loosen up the timing it's probably going to be faster. There is no real standard for DDR2-1066 though so it's really just an overclocker memory.

 

[Evilonigiri]

Theoretically, running 533MHz, or 1066MHz effective, at CAS 5 is faster than running 400MHz, or 800MHz effective, at CAS 4.

This is because 1/1066 x 5 < 1/800 x 4. The lower the time it takes to make a complete cycle, the faster.

In real life, you will hardly notice the difference.