DDR-cl 2.5, cas 2

I'm looking to buy some DDR, but not sure what specs I should be wanting. What's better: CAS2 or CAS2.5? I also see Cl 2.5--are there other classes? How about density? I've looked through quite a few of the threads here, but haven't found the answers. Please help!

Cl2 is a little faster than cl2.5.
The difference can vary from motherboard to motherboard.

There is a good article with comparisions here.

http://www.tomshardware.com/mainboard/02q2/020507/index.html

Many memory's rated cl2.5 will run at cl2 but it's not guaranteed by the mfg.

Placid

Thanks for the link. A nice short article that explained exactly what I wanted to know. I appreciate it.