Upgraded Dell Inspiron 6400 laptop RAM to 2.5GB

I have successfully upgraded the RAM of my Dell Inspiron 6400 laptop purchased 3 years ago from the original 512MB to 2.5GB now, and have been using this new configuration for more than 2 months without any problem.

Before this, I heard about the Dell Inspiron 6400 laptop can only support up to 2GB RAM, but now I've confirmed that it can support up to 2.5GB.

The original 512MB RAM residing in Memory Slot 1 of the laptop is of DDR-2 PC2-4200 SO-DIMM running at 533Mhz bus speed. I purchased another Kingston brand 2GB RAM of DDR-2 PC2-5300 CL-5 SO-DIMM which can run at 667Mhz bus speed and slotted it into the empty Memory Slot 2.



As shown in the photo below, the RAM on the left hand side is the original 512MB, and on the right hand side is the new 2GB.



When the laptop first detected the new memory, it displayed a message stating "The amount of system memory has changed." when boot up and seems to be hang at this message. I was a bit worry then, but later found out from Internet that I just need to be patient and wait for a while. The laptop then accepted the new amount of memory and no more similar message appear during boot up therafter.

It seems that both the memory can work together well without any problem, and can even work in Dual Channel Mode. They passed all the stringent memory test in Dell's Diagnostic Utility, and have worked happily for more than 2 months now.

Although the working bus speed has to synchornized to 533Mhz even the PC2-5300 RAM is able to work on the faster 667Mhz, but the performance affected is very much neglegible.

In the BIOS, it correctly detected 512MB + 2048MB = 2560MB RAM has been installed, but it says only 2559MB is available for use. Therefore, the maximum RAM supported by Dell Inspiron 6400 laptop is 2.5GB only, and it will be a waste to install any larger amount than that.



Windows XP detects a total of 2,619,768kB (or 2558.367MB) of RAM.



Notice that I have completely switched off the Virtual Memory by setting the paging file to 0. I have been using the laptop without any Virtual Memory in Windows XP for 2 months, and it just works fine. In fact, it runs much faster than before, and there is less harddisk activity now.