Cas Latency? What do i look for?

[w33tq]

I'm pretty sure that the lower the cas latency is, the faster the information is found/read in memory, but what exactly does it do?

I was going to get this Corsair XMS Package but it has a 3 cas latency. I've seen some of the same exact packages (for 100 bucks less) and they have 2.5 cas latency... is there any real difference? which should i get... ?

[ric449]

2.5 is the minimum you should go for, if you are concerned about speed that is. If it is max performance you want, get CAS 2. CAS 3 will hamper performance.

[w33tq]

is there any real difference between Corsair XMS and Value select? I see value select memory for less than XMS, and the value select runs at 2.5 cas latency, while the XMS is more $ and runs at 3.... Both are DDR400 and have bandwidth of 3.2GB/s...

Also, when newegg post the cas latency as "2-3-2-6", what does that mean? Are those th different cas latencies they can run at? or are there different levels of cas?

[mb26]

"2-3-2-6" are all different latencies along the path of the ram (sorry if that doesn't make sense).. there was a link to a crucial page that went through all of it a while back.. but i'm sure someone who knows more can elabourate on that,

Cas 2.5 can usually be 'overclocked' to cas2 if u pick the right ram, often without even changing the voltages.

[w33tq]

well.. i just want good ram (and a lot of it) to put in my soon to be new system, which will be an A7N8X-E Deluxe and a Barton 2500+.... A friend told me that corsair was nice, but i've also been looking at Mushkin, and they seem to have lower cas latency, for a lower price....

Is this ram any good: Mushkin 184 Pin 1GB(512MBx2) DDR PC-3200 Level One Dual Pack - Retail

??

I noticed that this ram (the link above) has a cas latency of 2-3-2..... that's one number (latency) less than the example i gave in the previous post... do i want more latencies, or less? or does it matter?

[mb26]

are u going to be overclocking the 2500?

mushkin is also good ram.

[ric449]

Less latency is always better. The memory you have picked there is quality RAM. I highly recommend it.

[not important]

I recently got that Mushkin RAM. 2X256's in an Intel build with HT. I'm very pleased with it.

[w33tq]

yeah.. i was going to overlock the 2500 a little...

[Spyda]

if youre on barton 2500, they run at 166FSB and DDR400 runs at 200FSB, you want to whack the 2500s FSB up to 200 and have the whole system running in perfect synch harmony Anyway, for AMD, its less important to have low latencies for anything other than CAS, and its DDR400, get some CAS2, its not expensive now and in plentiful supply

but for the other latencies its a little less important, im running an OCd barton 2500 with corsair XMS Platinum which is factory 2-2-2-5 latencies. I run the latencies at 2-2-3-8 and see better bandwidth, but this is a highly tuned machine to get every single last ounce of performance out of it, so if you arent looking for that, this last part wouldnt count