Question Abouth RAM Backwards Compatibility, etc.

[Dave Perry]

Hey everyone,

First, the standard disclaimer: I did read the RAM guide and it didn't tell me what I'm wondering, plus most of the talk was about Athlon systems and I have a P4.

First question is: I have a neolithic P4 2.2 in my Dell and I'm needing to make do with that while I accumulate parts for a better system. I will probably be going P4 3. something, Asus P4P800 in the new system. In the mean time, I want to up my system RAM to 1 Gig, but I'd just as soon use RAM that I will be able to put in the better system later, rather than buy more of what I already have in the Dell just as a stop gap, since I will be using the Dell later for applications not requiring a full Gig.

I have my eye on 2 512 MB sticks of Corsair PC3200. Can I put them in my Dell, which claims to have a 400 MHZ FSB and have it run okay while I wait for the parts for the new system? It will keep me from having to buy another stick of PC2700, which I won't really need in the Dell after I have the new system (I'll just put the old stick of PC2700 back in later).

The other questions revolve around the confusing speed figures. Right now I have a 512 MB stick of DDR533 PC2700. I bought it by mistake, since I don't have the 533 MHz FSB, I have the 400. How does PC2700 DDR533 compare to PC3200 DDR400? Which one is actually faster, or capable of being run faster? I'm assuming it's the PC3200, but the DDR533 carries what, on the surface, is a faster rating.

Is the difference that PC3200 can be run dual channel, thus achieving the 800 MHz speed that the newer boards can achieve, and that PC2700 DDR533 can only run single channel, thus having a maximum speed of 533 MHz with a 533 MHz FSB?

If I get PC3200 that is capable of dual channel operation, will it run okay in my Dell? Will it just run at 400 MHz, single channel?

 

[toadman]

Can't say for sure if your dell can run the pc3200 ram but more then likey it can.It just will run at slower speed.Also pc 2700 is rated at 333mghz not 533 so it is slower then pc3200 which is rated at 400 mghz.

 

[Dave Perry]

Thanks for the reply.

I should have clarified that. This is newer memory designed to work with the 533 Mhz FSB's on the new Dell Dimension 2400 motherboards. I believe it is supposed to be able to run at 533 MHz. How it technically differs from older PC2700 I don't know exactly.

 

[ts3433]

It doesn't differ at all from "older PC2700"--that P4's "533 FSB" is 166x4; quad pumped. That corresponds to DDR333 (166MHz). (For clarification, DDR533 is something like PC4300.) I'd say just get some Corsair Value PC3200 CL2.5; your system should run it, just at the lower speed, as said before.

 

[stevty2889]

Actualy PC2100 DDR (266mhz)(133x2) is for the 533fsb P4's(133x4). PC2700 is for either overclocking on a P4, or for an Athlon on the 166mhz fsb. The PC3200 DDR should work fine in your dell, it is backwards compatable, meaning it will run at the speed of your current memory.

 

[Gurck]

The pc3200 will be fine for your future rig at stock speeds, but may not overclock well or at all if you decide to try that.

 

[caivoma]

thankx guys, i always want to ask this question but i couldnt seem to post.