Can someone explain CAS. In reference to pc memory.

[biggiesmallz]

Can someone explain CAS. In reference to pc memory.

Is lower better?


I got some pc3200 Kingston Value ram that has been giving me problems suppositly because it is too slow for my cpu. http://forums.anandtech.com/messageview...atid=27&threadid=1856317&enterthread=y
It's CAS according to Memtest is 3-3-3-8. It was only $20 after rebate.

Memtest says that my cpu needs higher quality ram but this ram is 3-4-4-8 for $ 169.99 for a pair of 1GB http://shop3.outpost.com/product/3934288

I am confused.

Can someone please help me understand what the heck is going on.

Thanks

 

[Goi]

CAS(column address strobe) refers to the time(in memory clock cycles) between a read command and when the first data byte appears on the data bus, so the loweer, the better. There's no such thing as memory being "too slow" for the CPU as far as CAS goes though. It'll still work.

 

[Kakumba]

ok, do a search on memory timings, it has been discussed ad neasuem (sp?). And to answer the question, CAS is the first number (usually) in the set of timings, and lower is better. so 2-2-2-5 is very tight timings, 3-4-4-8 is pretty loose timings. look at OCZ Platinum PC-3200 and PC-4000 to see what some high performance memory looks like.

 

[GalvanizedYankee]

Read http://www.houseofhelp.com/forums/showthread.php?t=38136

Watch&listen http://www.corsairmemory.com/corsair/pr...s/tech/memory_basics/153707/index.html


Forget this is Corsair as your Kingston will be the same info.



...Galvanized

 

[JimPhelpsMI]

hi, GOI is right. Additonally CAS and RAS are the horizontal and vertical Mem Address strobes for refreshing the memory. They occur at less than a MS intervals to pump up mem bits/bytes by reading and rewriting each address. DYNAMIC Mem is really only a bunch of capacitors and a little logic to address and read/write. The caps bleed down quickly so have to be refreshed often. Longer intervals leaves more time for processing.
Hope this helps a bit, Jim