Memory size impact on timings

[Oren]

I've noticed that in many cases dimm modules with higher capacity have higher timings.

For example, Kingston Hyperx KHX3200A/512 is 2-3-2-6 while KHX3200/1G is 2.5-3-3-7

Why is it? Is it because the addressing is slower in high capacity modules?

Also, when memory modules have different capacity but the same advertised timings, will the lower capacity module still perform a bit better than the high capacity one? For example, will a HyperX KHX3200A/256 perform better than KHX3200A/512 although they both have 2-3-2-6 timings?

Thanks,

Oren

[Albuquerque]

I think the general concensus is that a smaller module will be more stable at higher speeds and/or tighter timings, but I couldn't begin to tell you why. The only thing is, if you need the space, two 512's will be more stable (usually) than four 256's. That's mostly due to the strain on the memory controller running four memory sticks instead of two...

I prefer the size and can live with a slight drop in timings. If I wanted THE uber-overclocker system, I wouldn't be on air cooling and an Albatron motherboard ;)

Edit: My brain turned on! I would assume the reason for higher-density modules being less overclockable and/or using loose timings would be they are higher-density in terms of transistors. A circuit with 200m transistors is going to resist clocking more than a circuit with 100m transistors.

That's not a perfect analogy, but it gets the idea across. That also doesn't mean I'm right, but that's my best educated guess :)

[Oren]

Thanks a lot! You even answered my next question about 4x 256MB vs. 2x 512MB without me having to ask ;)

[JKeefe]

Originally posted by Oren
Also, when memory modules have different capacity but the same advertised timings, will the lower capacity module still perform a bit better than the high capacity one? For example, will a HyperX KHX3200A/256 perform better than KHX3200A/512 although they both have 2-3-2-6 timings?
No, they will perform almost identically at the same speed. The only reason that they might differ is that if one stick is double sided and the other is single sided, and bank interleaving can more efficiently poll the double sided stick.

The reason smaller sticks might be better for overclocking has already been discussed - smaller sticks may overclock higher because they create less of a strain on the memory controller.

Personally, I prefer my GB of RAM :)