what is cas 2?

[blade_146]

Can someone tell me what the heck Cas 2 ram is? I've read posts about it but don't know exactly what it is. Is it better than PC 100 ram? Is it expensive? Is it worth it for overclocking? Thanks for any replies!!

[Roy]

CAS Latency is the real measure of RAM's performance. Study the SDRAM Survey at www.bxboards.com (http://www.bxboards.com) . Then study it some more. It's one of the better explanations of what really is important.

[Zonker]

How many clock cycles it takes to start reading the First piece of data out of a SDRAM, subsequent data in sequantial address' are accessed at the clock rate.


Micron Data Sheet

The CAS latency is the delay, in clock cycles, between the registration of a READ command and the availability of the first piece of output data. The latency can be set to two or three clocks.


[This message has been edited by Zonker (edited 06-24-99).]

[blade_146]

I may be way off on this if so correct me please, can you set the latency from the bios menu or is this just a different kind of memory all together? I read the survey on that link but got totally confused. The main question I guess is, can I tweak the ram like the cpu or is this stuff manufactored different? Keep the replies coming guys I'm learning, slowly but surely. Thanks...

[Zonker]

Most bios will let you adjust your SDRAM CAS latency between 2 and 3

[LJE2]

CAS 2 RAM will run at CAS 2 or CAS 3, CAS 3 RAM will only run at CAS 3, you make the setting in your BIOS, if you try to set CAS 3 RAM to CAS 2 you could have problems, (error's, crashes ect.). CAS 2, as the people before me have pointed out is faster, meaning the CPU can access the data contained in the RAM in 1 less clock cycle. When overclocking sometimes you have to slow down the RAM timing to make things stable, you can slow CAS 2 RAM down to CAS 3 but if you have CAS 3 RAM you can't slow it down any more it's all ready set to the slowest setting.

[This message has been edited by LJE2 (edited 06-24-99).]

[BBA]

LJE2, thats a good suggestion only that I always ran my CAS3 10nsec ram at CAS2 at 124Mhz, without any problem, yet my CAS2 8nsec dimm failed after 3 months at 112Mhz!

BBA

[blade_146]

Ok here's another question. In my bios I noticed that the "cyle length" was set at 3 and the "cache timing" was set to fast. If I changed the length to 2 and the timing to fastest would I see any improvement? Also my AGP 2x mode was disabled, should I enable it? Thanks for the replies.

[LJE2]

BBA
Well, what can I say, I was just tellin things the way they're supposed to be, but as we all know that isn't necessaraly so in the real world.

[LJE2]

It won't hurt anything permenantly to change these timings go ahead and try it, I don't think you will notice any difference, if you run benchmarks it might show a slight
increase, but what will probably happen is your system will become unstable, if this happens just change it back. If your video card is 2x, yes change the setting to 2x, if your AGP card is 1x you can't make it run faster by changing this setting, it just won't happen