DDR3 voltage and timings specs question

[AN5]

This for AMD Phenom x4 955 with AM3 motherboard (Asus)

The memory I am interested in is DDR3-1333, 4GB (2x2GB). I see that memory is available with different CAS numbers 7, 8, 9 and different voltage numbers: 1.5V, 1.6V, 1.65V, 1.7V, 1.8V.

Is there any difference if I am not overclocking?

What voltage is a better spec?

Is there any benefit to getting 7ns CAS vs 9ns CAS?

I am leaning towards this one G Skill but I want to understand if cheaper memory with slower CAS will work the same.

Also, why do companies have separate products for the PC3-10600 vs PC3-10660 vs PC3-10666? Is there really any difference?

Asus does not seem to have a QVL list for memory. Is that correct?

[Masaki 7-11]

Originally Posted by AN5 This for AMD Phenom x4 955 with AM3 motherboard (Asus) The memory I am interested in is DDR3-1333, 4GB (2x2GB). I see that memory is available with different CAS numbers 7, 8, 9 and different voltage numbers: 1.5V, 1.6V, 1.65V, 1.7V, 1.8V. Is there any difference if I am not overclocking? What voltage is a better spec? Is there any benefit to getting 7ns CAS vs 9ns CAS? I am leaning towards this one G Skill but I want to understand if cheaper memory with slower CAS will work the same. Also, why do companies have separate products for the PC3-10600 vs PC3-10660 vs PC3-10666? Is there really any difference? Asus does not seem to have a QVL list for memory. Is that correct?

The difference in performance between CAS latencies is usually pretty low, so any latency works as long as it's compatible with your motherboard. Asus does have a QVL for memory, you can find it under their product specs page for the motherboard; from there you will have to download the file, unzip it and open with some type of PDF reader.

If you are not overclocking, it's usually best to get lower voltage ram, latency will have some determination on performance, but not very much, so getting a higher latency ram will not have a large impact on performance versus getting a low latency ram.