Impact of CAS-3 vs CAS-2 RAM vis-a-vis overclocking?

[Dan]

Crucial has some great pricing on excellent RAM. (And free 2nd day air shipping -- see the Hot Deals Forum.)

I have a question though. There is a $35 delta between the CAS-2 and CAS-3 256MB sticks. All other specs appear the same.

I overclock my Duron 700 to 1083MHz using two 128MBH sticks of Mushkin REV 2 CAS-2 RAM. Will I be able to overclock like that with the CAS-3 Crucial RAM? (I plan to order two sticks and really don't want to spend an extra $70 if I can avoid it!)

 

[Spoooon]

Depends on how high your increasing the FSB. Since you're probabaly like the rest of us, you can't really get the FSB any higher than 110. PC133 CAS2 ram is basically guaranteed to run at 143+ at CAS3, and depending on the quality it may even do CAS2. With a CAS3 stick, you won't have the option of increasing the CAS latency help overclock the memory. Though, I have a 3-3-3 stick that will do 143 at CAS2, so you never know. So, I guess I didn't really answer your question.

 

[Ulysses]

The difference in overall system performance when running your RAM at CAS 2-2-2 vs. 3-3-3 is on the order of 5%, although it depends on what you are doing with the PC, of course. So a 900 system @ 3-3-3 performs similarly to an 850 @ 2-2-2, generally speaking.

I'm not familiar with the Abit KT7 BIOS, but if you run your CPU at 110, then I'd imagine your RAM is, or could be set to be, running at 143 (110 + 33) - but I may be wrong on that. To run at CAS 2-2-2 at 143 you'll need a premium grade of RAM marketed as PC133 CAS 2-2-2 at the very least.

Only you can decide if it is worth it. You may already have enough RAM, depending on what OS you use and what you do. See this, which is pretty realistic.

 

[Dan]

Thanks for the replies.

My current OS is Win98SE although I sometimes run Win2K Pro as well. I have 256MB RAM right now but want at least 512MB. I'm getting 1083MHz out of a 700MHz chip by using 103x10.5. I can't get either of those factors any higher and boot into Windows.

 

[Ulysses]

If you are running your CPU at 103, then your RAM is running at either 103 or 136, depending on how you set it, I believe. If it's at 103, then just about any PC133 RAM will run at that speed at CAS 2-2-2. If you're at 136 you'll need a CAS 2-2-2 PC133 RAM, but probably not a premium grade like the stuff that's meant to run at 150 MHz, say. Maybe something like the Mushkin Rev. 1.5. If you have Rev.2 now, though, it seems a shame to step down when getting more - not that there is anything wrong with Crucial, of course.

 

[Myrddin]

I'd go with the higher quality RAM for $70, if only because if you decide to at any point switch to a KT133a instead of going DDR then the better RAM may provide better results.

Personally when the KT133a's do come out, I will probably go with 128 MB PC150.