RAM Questions

[Zanfib]

I'm buying the stuff to build a new system (my first) and I was wondering how much of a difference (both speed-wise and stability) is there between CAS 2.0 and CAS 2.5 DDR RAM (PC3200 for a dual-channel setup)?

I won't be overclocking (yet) so all I need is good fast performance at stock speed. I'm on a limited budget but if there is an obvious difference I'll spring for Corsair XMS (CAS 2.0) vs. Kingston (2.5).

Thanks.

 

[wfbberzerker]

if youre on a limited budget, go for whatever's cheaper. there is a slight difference in speed, but not enough to warrant the difference in cost.

here's a better explanation as to what cas is.

 

[Cerb]

The difference with 2-2-2-x-1T, 2-3-3-x1T isn't much.
2.5-3-3-x-2T is noticeably slower, but not *that* much if you're tight on the cash.

 

[Zanfib]

Ok, first I'll declare I'm a newbie, so what do all the numbers listed for the ram specs mean?
For example:

2-2-2-x-1T

Means what? And when I'm buying how do I go about checking all these things. I'd ideally like to buy from my local store and they carry Corsair XMS, Samsung, Kingston, and some el cheapo stuff. There is no real mention of the above numbers only the general stuff like CAS, ECC/non-ECC, and for RDRAM the pin counts and 16bit/32bit.

Any advice would be appreciated.
Thanks

 

[bendixG15]

Go to the web site crucial.com for the answers to questions.

 

[Zanfib]

I checked before I posted.
I can't find any clear answers about what the numbers mean.
All there is on crucial's site is explainations about DDR Speed, CAS options (which had no real anwer on real life impact of CAS 2 over 2.5, which is why I posted in the first place), and densities.

If there is a FAQ or help page I'm missing let me know other wise I still don't know what those four numbers mean.

 

[Cerb]

I can't find a good FAQ on the subject, but basically it's a number of clock cycles to do stuff. Time between the request and actual access, read, write, etc. Basically, the lower timings, the better....except that the 4th number, tRAS, IIRC, has no real bearing on the performance, even in synthetic benches like sandra's memory benchmark. IIRC, the 1T and 2T are the command rate...how often it can send a command to the RAM.

 

[Zanfib]

Cool, thanks. So for the most part these numbers will be controlled by the quality of Ram and how aggressive my timing settings are? I'll be putting them into either an 875 or 865 (when available) Intel mobo so I'm sure if they are bios options they will be properly explained in the manual.

Thanks all.

 

[0roo0roo]

just go with price, and get atleast 512+ mb.