Questions about RAM Performance

I was wondering if someone could clearly explain RAM performance in terms of low latency vs faster Speeds. I understand that you want the latency to be low and obviously the speed to be high, but which one is more important and how can you recognize a good balance of the two.

Second question, in terms of PC performance how do higher capacities (memory size) vs RAM performance (speed/latency) compare? IE: 2gb of slower RAM vs 1gb of a faster RAM.


I've been trying to get a better understanding of this for a while but haven't found much that really explains this. A link to an article that this explains this would be just as good.

If it matters, I'm looking at RAM in terms of best performance for gaming.

Thanks

 

I'm going to try and answer your question, I'm not sure how much sense I'll make:

Speed (in MHz) and latency are two different measurements of RAM's speed.

MHz speed refers to how fast data can between the motherboard and the memory module, while latency determines how fast info can be looked up and used in the RAM stick. Latency refers to how fast the chip can "recycle" between uses.

Both are important, but capacity is by FAR more important than speed (at least at today's specs)

2 GB of slower (only slightly) memory is better than 1 GB of faster (slightly) memory. I say slightly because there is really not that much of a difference between memory these days, at least one that you would notice.


http://en.wikipedia.org/wiki/CAS_latency explains CAS latency; for other links try searching wikipedia.

 

vespoli explained very well, but since I am more new at this I will dumb it down (for myself), and I am talking current RAM DDR2, My 533Mhz is mostly going to have a lower latency than 667Mhz but 667Mhz speed overcomes that so if given the choice go faster! More Ram is better, even over Dual channel! But if you can get Dual channel without less amount of memory, get it!

 

Thanks for the responses.

Let me see if I have this right... more memory is most important then speed, then latency? (in terms of DDR2)

 

Yes. Applications don't search around for the fastest memory to use, rather they look for a certain AMOUNT of memory to use.

Let's say firefox is using 80 megs of memory (if you have alot of windows open), then you decide to open Adobe photoshop and Fireworks and Studio 8 apps, well if you're using 512 megs of ram, your computer will come to a crawl, no matter how fast that 512 is.

However, if you have 2 gigs of memory, switching between applications will be alot less painless, as well as those apps loading alot faster initially.