2 Pairs of RAM with different timings & frequencies

[Nads]

My Dell Dimension 5100C came with a pair of 256MB PC2-4300 (266mhz) RAM:

 

CAS# Latency: 5.0

RAS# to CAS#: 4

RAS Precharge: 4

Tras: 12

Trc: 16

 

I've just installed a pair of 1G PC2-5300 (333mhz) RAM:

 

CAS# Latency: 5.0

RAS# to CAS#: 5

RAS Precharge: 5

Tras: 15

Trc: 20

 

Totaling 2 1/2 Gigs.

 

I have limited knowledge of RAM timings and configurations.

 

- What is the optimal way to tweak this?

 

- Do they need to run at the the same timings and/or frequencies for optimal performance?

 

- Would it be better just to yank the originals out/are they slowing down the new stuff?

 

Any information you can provide would be very helpful. Thanks in advance!

[Doobzilla]

I hope that I don't sound too preachy.

First things first, take out either the new memory or the old memory. What you are doing right now is causing the old memory to dictate how the new memory operates; i.e. speed, timings, voltage, etc. (not that there is much more to it). Once you figure out which memory to take out, then you can begin to tweak whatever you leave behind (I would suggest running your new memory instead of the old stuff).

Then start at the stock settings for you memory (hopefully the new stuff). and tweak one option at a time. About the only way to get your CAS down is to up your voltage slightly and/or lower your memory speed. That is why I don't suggest starting there. Instead start at RAS and lower it one notch. Save and exit. Run Memtest86+ 1.70 overnight or while you are at work. When you wakeup/get home, check it, if it shows no errors after at least five hours (eight is my preferred time), try tweaking another setting. Perhaps the RAS Precharge this time. Do so until you encounter an error. When you encounter an error, undo what you last changed and fly with it.

That is how I do it now (my old way was just to tweak and see if anything happened in an OS that was detrimental to my calm, not a good idea). Hopefully I haven't steered you in the wrong direction, I'm sure that if I have one of these other guys will surely set you back on the right track. Good Luck!