2 RAM sticks wont work together - why?

[sidewinder]

I have been upgrading the caretakers personal laptop for him, before he had 2 x 256MB RAM and wanted 2 x 512MB to give him 1GB

I ordered both modules direct from Crucial, although at different times, using their configurator tool.

They both work perfectly - on their own. When I put them in together, Windows always blue screens justas it boots up or just after

I wiped the system and used the recovery disks and the problem persists. I couldnt even use the discs with both modules in, that crashed as well

Doesnt matter which slot each is in, it just wont get any further than starting Windows

But what can I say to Crucial? Neither module seems to be faulty on its own, so do I need to send them both back? Anyone else had anything like this before?

Im running memtest on both sticks now and so far theres over 900,000 errors
I will try on both sticks seperately when its done

The laptop is an Acer Aspire 1500

[Disease]

Sounds like they are not matched pairs, the laptop may require matched pairs.

[ChrisC]

Exactly my thoughts.

Chris

[sidewinder]

Just checked for that on Crucials site

http://www.crucial.com/uk/store/list...re+1500+Series

"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."

However if they are wrong I suppose we have a case for replacements

[ChrisC]

Yep. I would contact crucial, explain the problems etc and if you only got it recently they should help out really!

Chris

[Disease]

IT's the laptop that might require matched pairs, certain Intel CPU's require that you have matched pair memory.

[Geoff]

Also try a bios update.

[NetDiag]

It's pretty obvious whats going on here. That laptop is fussy as far as memory is concerned which is always the case especially with Intel based systems.

If you ordered them at different times it doesnt matter that they are the same speed and cosmetically look the same as it's possible to have variations on components and timings from different batches of ram from the manufacturer. This has happened to me in the past and a lot of people I know.

Here are some things I would personally try:

Try and find the ideal memory timings for the ram in relation to the make and model of laptop. Should be able to google for this and try to set the memory timings manually in the BIOS. Sometimes some hardware doesnt recognise the settings from the SPD chip on the ram or may get confused if they are from different batches of manufacture.
This will effectively underclock the stick of ram that is faster than the other if this is the case.

You could also underclock the ram. If it is 400mhz they might work together at 333mhz but thats a major performance loss and a bit compromise.

Failing that the ideal solution is to send them back and get 2 identical matched pairs from the same batch.

@Geoff, In my opinion there is no need to update the BIOS to resolve this, because the tolerance to ram variety is probably set by the hardware components soldered onto the mainboard and not in the BIOS.

Still, you could try it but I wouldnt hold out in hope that this will resolve the issue.

[ChrisC]

from 400 to 333, do you recon the end user will notice the miliseconds difference in performance?

Chris

[NetDiag]

from 400 to 333, do you recon the end user will notice the miliseconds difference in performance?
Chris

Probably not, unless they are educated geeks like many of us on this forum! The performance loss would only be more noticable under heavy load performance apps and not really MS Offirice or Internet Exploder!

[plexer]

running memtest on both sticks now and so far theres over 900,000 errors

hmm I'd say one or both of them is knackered then.

Ben

[Disease]

Aye Knackered.