System Memory

I have few questions. First is what does Cas Latency do for ram? I think its like a speed. The second question is if it is better to buy 2 sticks package. Or buy 1 stick packages and get 2 of them.

CAS stands for Column Acces Strobe which is the ratio between column access time and the clock cycle. Basically in layman terms - how fast the memory can access something across a column (think of memory as an Excel Spreadsheet).

RAS is for Row Access Strobe - How fast the memory can access something across a row (again the whole spreadsheet analogy).

This is all refered to as a memories Latency. Wikipedia defines latency as a time delay between the moment something is initiated, and the moment its first effect begins. More specific for RAM, as the amount of time a computer needs to wait to get data from RAM.

Oddly enough - the slower the memory runs the lower latency it has. Now as RAM technology advances the relative latency to clock speed also goes down. So you can now have faster clocked memory that runs at the lower latency.

For dual channel memory - get the 2 sticks in 1 package. They are specially picked to work with one another in a dual channel setup.