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Numpty memory question
GeoffT - 8/6/08 at 09:50 AM

Apologies for a question on what is probably pretty basic stuff to the computer literatti (?) amongst us, but something I'd just like to clarify.

I need to increase the memory on my desktop pc. It currently has 2 x PC2100 DDR 256mb sticks, but a quick bit of research seems to indicate that I can also use PC2700 or PC3200 - is that correct?

Also I was intending to use just one 1GB module initially (and add a further 1GB later) but apparently that means it won't be operating in DDR mode - is this really an issue, or something I won't notice in real life?

Any advice welcome!

Rek - 8/6/08 at 09:56 AM

if you go to the crucial website www.crucial.co.uk they have a memory advisor app. that will tell you what you can run. generally you dont want to mix speeds...

BenB - 8/6/08 at 12:16 PM

If you mix speeds the memory will run at the speed of the lowest memory. The later "PC" memories are backwards compatible (make sure you don't get the cheap high density modules off Ebay as most motherboards won't take them).

But- you need to take into account the max speed of the motherboard.

If your motherboard will only take PC2100 even if you filled it with PC3200 it would only run at PC2100 speeds.

...but as few manafacturers make PC2100 anymore it's often more expensive to buy than PC2700 or PC3200. So if your motherboard can only handle PC2100 memory you're better off keeping your PC2100 memory and slotting in a new PC3200 or PC2700 memory (whichever is cheaper, it'll only run @ PC2100 speeds). If your motherboard can handle faster memory though, you'd be better off upgrading all the memory to the fastest chips your mboard will take.

GeoffT - 8/6/08 at 01:22 PM

Ben - you've got me worried with the warning about the ebay modules - are these ok?

ebay stuff

tks - 8/6/08 at 02:40 PM

quote:
Originally posted by GeoffT
Ben - you've got me worried with the warning about the ebay modules - are these ok?

ebay stuff


looks crap to me...(atleast the advert is)

what have a dancing couple to do with memory???

Tks

geoff shep - 8/6/08 at 02:41 PM

For the price difference, which is not great, I think I'd go for a reputable UK supplier - it will be quicker and easy to return if its wrong or bust - I usually use ebuyer. A single 1Gb chip should work fine, you may even be able to add one of the old chips and get 1.25Gb, its worth a try. Here's a 2700 one but they have all speeds - Ebuyer

GeoffT - 8/6/08 at 04:53 PM

Thanks for the help chaps, Ebuyer memory now ordered

MikeRJ - 8/6/08 at 10:03 PM

quote:
Originally posted by GeoffT
Also I was intending to use just one 1GB module initially (and add a further 1GB later) but apparently that means it won't be operating in DDR mode - is this really an issue, or something I won't notice in real life?

Any advice welcome!


It will still work as a DDR (double data rate) module, this is intrinsic to the memory technology. What you won't benefit from is the increased memory bandwidth that two modules working in 'dual channel' mode can bring.

In simple terms, memory has a certain latency associated with it, i.e. when you ask for data it takes a certain amount of time for it to be returned which limits throughput. By using two modules, you can ask the second module for the next bit of data whilst the first one is in the process of fetching the first bit of data. This can theoretically double memory bandwidth, in practice gains are somewhat lower.

Whether you'll notice depends on the kind of applications you run. A typical home user will probably notice very little difference, if you are a hardcore gamer then it can make a significant improvement.

[Edited on 8/6/08 by MikeRJ]