Which RAM is right for me

[DeadSeaSquirrels]

Currently I have 512MB of DDR 2100 RAM in my Abit AT7. I think it is Unbuffered, unregistered that is in there. The few questions I have:

Why is registered RAM so much more expensive, and what does it mean to have a memory array of 64 or 72 bits wide?

Can I mix registered and unregistered RAM?

Can I mix RAM of different speeds, like a PC2100 with PC2700?

Can I, or should I, mix RAM sizes that are different? Currently I have to sticks of 256MB CL2.5 each, can I buy a 512MB stick, and have no degredation in quality?

I guess that is it for now. Thanks for the help.

 

[BentValve]

You cannot mix registered ram with unregistered, you can mix PC2700 and PC2100 but why?
Run your motherboard at 166fsb if it has 1/5 dividers in it and get some low latency PC2700 for it and run it at max timings.

 

[bgeh]

having 64 bits is normal RAM
having 72 bits=64 bits + 8 bit ECC

 

[Ilmater]

Someone with more time on their hands can explain exactly what unbuffered and unregistered means, but suffice it to say that it's really only necessary to use it for servers where data integrity is critical. In your home system, it's not necessary.

I'm not 100% sure what the array means, but it's something to do with the density of the chips. I don't think it matters much.

You can mix registered and unregistered RAM, but the benefits of the registered stick (ECC or Error Correcting Code) is lost.

The speed is only a rating. In other words, a PC2100 stick is only rated for 266MHz DDR, but a PC2700 stick is rated to run at 333MHz DDR. You can run them both in the same machine, but you're only guaranteed to run them at the speed of the slowest stick.

The reliability of mixing RAM sizes depends completely on the board and chipset. I would ask others with an AT7 if they've done this and how it worked for them. If you mix manufacturers, there's a definite chance that there will be incompatibilities. It's a crap shoot, but the odds are in your favor. Good luck!

 

[DeadSeaSquirrels]

Thanks for the info everybody, i think I'll stick with the PC2100, just get another stick of 512MB, I'll stick with Crucial.

Hopefully the difference in sizes won't make a difference. Thanks

 

[microAmp]

Robbed from Crucials FAQ.

What is the difference between buffered and registered memory?

 

[AtomicDude512]

Originally posted by: DeadSeaSquirrels
Thanks for the info everybody, i think I'll stick with the PC2100, just get another stick of 512MB, I'll stick with Crucial.

Hopefully the difference in sizes won't make a difference. Thanks

DONT! Crucial has had compatibility problems with some KT400s and most nForce2s! I would get something like Kingston if you are a budget buyer, it is reccomended all over.

 

[thatbox]

But didn't Kingston reportedly have the same problems that Crucial had?

 

[MikeMike]

IT IS ONLY PC2700 that has the problems with the mobo's!!

and it is only Kingston Valueram that has problems, hyperx has none. Samsung original is some amazing memory as is corsair XMS