Memory Mystery

Greetings, wise ones! I am a long-time lurker and beneficiary of the wisdom here.

I am currently stumped by the behavior of my eMachines T3958. Running Win XP SP 3.

It has two memory slots in it. Its documentation says it can handle a maximum of 2 GB of RAM.

When I run the scan @ crucial.com, it says that it can handle a maximum of 2 GB of RAM.

The machine tells me that it has 1.25 GB of RAM installed when I click on the Properties of My Computer, as does the crucial.com scan.

Here's the mystery: I have 2 1 GB sticks of RAM (identical, Corsair), installed in the beast.

I have tried to find if there's some odd setting somewhere disabling the second stick of RAM down to 256 MB, but have found nothing. Going into the BIOS setup, although always a refreshing change of pace, did not enlighten me.

Thoughts, anyone? More information needed? The machine is running fine but I would like to get the benefit of the remaining 3/4 GB of RAM that is languishing in my machine.

Thanks,

FJM

 

How much memory did the BIOS say you have?

Test the modules individually, and see if they both read as 1GB when installed alone. If they do, test the two memory slots the same way.

 

Yup- Mimsy pretty much covered the bases. One more thing though- if you're using the built-in onboard video, it will use a portion of the memory, but this is very seldom over 128mb, 256mb is very rare for shared on-board video. So it doesn't account for all of the "missing" memory, but it does account for some of it....

EDIT- I did some research, and it appears that the motherboard is designed to use DDR333 (or PC2700) memory, if you're running DDR400, this may have something to do with it. Ordinarily, running DDR400 in a board rated for DDR333 is a non-issue, and the memory will simply 'step down' and run at the slower speed, but this may be the cause of the weirdness (or a partial cause anyway).

 

BIOS said I had 1.25 GB (although not expressed in those terms, it expressed it in MB).

Will do. Thanks.

 

When I pull out the sticks I'll take a look. They probably did sell me DDR400...

EDIT--sorry about the consecutive posts--was trying to merge them into one, but it didn't take.

 

Argh! I have no edit button, so no way to post results other than adding an additional post.

Stick one in second slot (helpfully labeled by BIOS as 1): 256 MB.
Stick two in second slot: 1 GB.

Well, that appears to be the problem.

My two current sticks (both the good and the defective one) are both DDR333.

I have a spare, brand-new 1 GB stick otherwise compatible with my machine that is DDR400.

Is it acceptable to keep the "good" DDR333 stick I have and use the new DDR400 stick in my other slot? Or do I need to have them match exactly?

Many thanks,

FJM

 

Maximum Memory: 2048MB
Slots: 2 (2 banks of 1)
Standard Memory: 512MB removable
USB Support: 2.x Compliant

Q: Do I have to install matching pairs?

A: No.

No, you can install modules one at a time, and you can mix different densities of modules in your computer. But if your computer supports dual-channel memory configurations, you should install in identical pairs (preferably in kits) for optimal performance.

according to crucial.com you do not have to install a matching set. I'd run it by Mimsy and dlb just to make sure..

 

This computer definitely is not advanced enough for dual-channel configs...but I'll wait for Mimsey to give me the last word on this. Thanks.

 

Nope, you don't need to match them exactly, the motherboard is smart enough to use them together. It will simply do what dlb said in his post earlier and run them both at the speed of 333MHz. With the new added to the good old one, both the BIOS and operating system should report 2GB.

and psst.... it's Mimsy, with no e. Like the borrogowes

 

That was my fault, FJM quoted my message before I could edit the name and post it right.

Sorry
Buggabear

 

Oops, Mimsy (note lack of "e"), thank you!

My system now reports 1.99 GB RAM. I can live with that.

Thanks to all for your prompt help in resolving this mystery.

Gratefully,

FJM

 

That's most likely caused by that on-board video function that dlb mentioned in his post, so essentially that's a good thing that means everything is working the way it's supposed to.

Enjoy the "upgrade" from 1.25GB to 2GB :-D