pc133 @ cas3 or pc100 @ cas2?

[chexi]

Which is better, ram running at pc133 @ cas3 or at pc100 @ cas2?

 

[DeathroweR]

Buy PC133 CAS3 and set it to 2 and it will run fine at 100MHz

 

[shiznut123]

it wouldnt matter because the pc133 would be set to 100 mhz

 

[chexi]

Hmm *scratches head*, I'm a bit confused. Is what you are saying that CAS2 must be set at PC-100 to run on any system? I'm not that familiar with RAM, so I don't know if you can run at 133 mhz at CAS2. If this is so, am I better off running at CAS2 at 100 mhz or at CAS3 at 133 mhz?

 

[Grminalac]

Hello,
It all depends on what type of ram you have...
The best case scenario would be to run it at 133 CAS2 which would require a higher quality ram. (not expensive now with ram prices falling) Find out what kind of ram you have.
What are you running anyways? Adjusting a + - option in the bios? A KT133?
The best way to decide this is to download sisoft sandra try the memory both ways and test using the memory benchmark. Stick with whatever gives you a higher score. My guess is 133 cas2, but I am not 100% certain.

 

[Quickfingerz]

Just a question to all you anandtechers.

How often is this question asked per week? I'm curious.

 

[DeathroweR]

Quickfingerz -

A question for you -
Do you know how to do a search?

j/k

 

[Redwingsguy]

Yarr what does CAS 2 or CAS 3 mean, I know CAS 3 is slower but why? Cuz I noticed when I OC'ed my 600e, I had to adjust my ram from 2-2-2 to 3-3-3 and my performance accually dropped at 800 rather than running at 600

 

[Grminalac]

Well I cannot remember the exact technical explanation behind memory latency, but cas2 and cas3 is the column access time. Basically from what I recall cas2 setting does in 2 cycles what cas 3 does in 3. Its just the timing the motherboard uses, not a type of memory. Its just that some memory cannot support the speed. I'm sure some techie here can give a long boring explanation noone cares to read.
As for your problem i suggest you look in your bios and see if there is a setting to adjust memory speed. If you have a apollo pro 133A chipset motherboard (and possibly a 815 but i am not sure) there should be a setting to add or subtract 33 mhz to the memory speed. Meaning you could run the 600 at 133 FSB giving you the 800, but toggle the setting to adjust the memory speed to -33 i.e. 100 allowing you to set the memory to cas2. whats also nice is the ability to adjust the fsb higher than 133 (if your processor and perpherals can handle it) and still run the memory under 133. You might want to try setting your fsb to 150 and toggling the -33 setting then you would have a 900 with memory at 117.

 

[chexi]

Thank you to those who have provided meaningful help.