upgrading RAM, mixing brands, CAS?

[arameth]

I'm looking for some advice, hopefully wanting to avoid a problem, so I'm doing my research now.

I recently purchased a Dell Dimension 4600, P4 2.4ghz running 800FSB. It came with 256mb PC3200 RAM (2x128, 400mhz). I'm under the impression this memory is rated as CAS3. I also understand that my motherboard has 4 memory banks..and memory must be installed in pairs. I want to upgrade, and I'll be adding 512MB (2x256) or 1024 (2x512), depending on prices.

Here are my questions:

1. Can I purchase a different brand of RAM, rated PC3200 CAS3 and expect little or no problems? I'm pretty sure I can, but wanted to get some feedback.

2. Can I purchase a higher speed memory module (PC3200 CAS2), and "mix and match" with the current memory (PC3200 CAS3, though they'd be loaded in different banks...any problems doing this? Or is it just throwing money away?

3. How big of a difference in performance could one expect from using CAS3 versus CAS2.5, or even CAS2?

If anyone has had any experiences they would care to share, I'd appreciate it.

Thanks!

 

[arameth]

Anyone with any experiences, good or bad? Advice is greatly appreciated.

 

[kag]

I might be wrong... but I know for sure that in the old days, it would run at the speed of the slowest stick.

 

[Sheriff]

No expeience with the set-up you mentioned but most RAM is a chance by Mix n Match. I've done it many a times with success if that helps

 

[Mavrick007]

It should not have a problem by mixing and matching any more than two sticks of the same brand would give, but it just depends on the quality of the sticks.
You can buy a faster stick and pair it up with the slower sticks but they will run at the slowest speed of all the sticks and will not really benefit you "now", but
if you planned on using it in another computer in the near future, then if the price was right, I would say go for it.

Performance will not be alot different between cas 2, 2.5, or 3 unless you want the highest artificial benchmark you can get.
This will hardly be visible in any application you use.

You may be able to push the ram to lower timings with the ram you get anyway. I have some ram that was rated poorly, but I was able to push it to the fastest
my mobo would allow 2-2-2-5-T1. It gave me several hundred extra 3dmarks in 2001SE but I don't think it would be noticed in a real world app.

DDR ram doesn't have to be installed in pairs, that would be old ram such as the old RDRAM. If you want dual channel, it would have to have at least one pair, but it will
still work with just one stick or three sticks if you have three slots.

 

[arameth]

Thanks for all the feedback....this is exactly what I needed to know!