Question : Problem: Not all the new memory added is being recognised

The PC I have at home is a DELL Dimension 4550. It runs Windows XP SP3 (Home Edition). Its about 5yrs old and is in very well maintained (tuned, cleaned etc and looked after)...It has been getting a bit creaky when it comes to handling photos as they have become larger with the larger mega pixels cameras today and I use Photoshop Professional edition for editing...

So I bought new memory for it. It had 768MB (256 & 512) of RAM across two slots (only two slots) on the motherboard, so I bought two 1GB memory modules to get me up to 2GB of RAM across the two slots.  I am pretty sure its the right memory I got (see below).  I have installed the memory and the BIOS picked it up (A03 version). In fact I can see the 2GB in the BIOS (F2 at start up), DXDIAG tool, Task Manager, System Properties and when I use the CPU-Z tool from the net it confirms its all there. Also I ran the Windows Memory Diagnostic tool (mtinst.exe) last night and it found no issues. I am on the side of it is not a hardware issue and most likely a software issue, but not 100% sure.  

One thing though, when I go to the DOS command and type mem, I see the following: (but I read also "Windows XP does not use this command" so it might be irrelevant
 1048576 bytes total contiguous extended memory
 0 bytes available contiguous extended memory
 941056 bytes available XMS memory

The memory in it was: Samsung DDR-DIMM - 184-PIN - PC2700CL2.5 Non ECC etc
The memory I bought (x2) was http://www.komplett.ie/k/ki.aspx?sku=306537 (Crucial make)

All works fine until I go above the 1GB of RAM where the other 1GB does not appear to recognise the rest of the ram and I start getting virtual memory issues....I have also adjusted the Swap file size.

I find it strange that I can see the memory through all the other usual utilities but I can't use it. I did notice that the 1GB modules have chips on both sides while the original ones have them only on one side, but I believe this does not matter for DDR - DIMM memory modules.

One last thing was when I ran Crucial Memory / Computer compatibilty tool on their web site, it did see to say that 512MB in each slot was the max, but I expect that this is because for a long time now 1GB module were not available.

I would really appreciate any assistance on this matter.

Thanks SL

Answer : Problem: Not all the new memory added is being recognised

I find it strange that I can see the memory through all the other usual utilities but I can't use it. I did notice that the 1GB modules have chips on both sides while the original ones have them only on one side, but I believe this does not matter for DDR - DIMM memory modules.


you comment above: this does matter for certain motherboards expecially older ones, if you motherboard only has 2 slots I would suggest taking your ram back and asking for single sided ram, as your motherboard quite possibly cannot handle so many banks of memory. this has been an issue i have had previous times and always now only buy 1 sided ram sticks.