Cas Latency

How much of a difference will i see between memory with 5 cas latency and 4 cas latency, both are 2 gig setups using 2 sodimms of 1 gig DDR2 667mhz.
Will there be a noticeable difference, i am not upgrading from one to the other, but upgrading to one or the other.

 

you wont notice it.

 

Do you have links to both of the RAM modules? I've never seen DDR2-667 SO-DIMMs with a CAS lower than 5.

I do agree that you're not likely to notice a difference, although I would definitely go for the lower CAS sticks because it will bump up your overall system performance (although once again, probably not to a noticeable level; performance is already blazing fast with these new systems).

 

It is actually in the hot ram deals, it is a corsair bundle, i was also surprised when i saw it. And actually it costs the same as the other 2 gb bundles.

 

Going with the lower CAS latency helps the performance, but how much is the price difference ?
EDIT : If it's Corsiar and there is no price difference, you should definitely go with it.

 

I have seen a few cas latency 4 667's around. Still tho outside of a memory bench you wont see the difference. You definitely wont notice it in every day use or in a game.

 

I think this is the CAS4 667mhz ram he was talking about, but nowhere on corsair's homepage can I find the 1GB modules that have the CAS 4 timing. All the 667Mhz products show a CAS of 5, perhaps fry's made a mistake with this one. I agree with Chaz I have never seen 667Mhz ram for notebooks with a CAS lower than 5.

 

Since you are using the ram in a notebook, it is possible that the notebook will still run the ram at cas5. Of course having the lower latency ram is nice and in case the notebook does run at the lower cas setting, that would be great. Just don't be surprised if it still runs at cas5.

Just an example, I have Sony SZ model and the default 512MB ram it came with ran at 533MHz. As soon as I got it I pulled the ram out and put in 2GB of 667MHz ram, unfortunately it still runs at 533MHz. Sony basically limited the SZ to 533MHz, which gives me reason to believe that other manufacturers may force the ram to run at cas5 even if the ram SPD says it can run at cas4.

Assuming it does run at cas4, in certain instances you will notice the lower cas setting. Specifically encoding/number crunching types that really saturate the FSB/memory. However I'm sure most people won't since they generally don't run these type of programs on notebooks.