Keith Shirley

It’s not all that long ago where the idea of 4GB of memory in a PC would have seemed exotic. I find things tend to come in batches and I just had the third person asking me about this in the last two weeks I thought I’d pass on what I’ve been saying.

Basically – if a machine is installed with 4GB of memory – then most likely the operating system will not be able to see it. Due to the way the address space is mapped there is a limit in 32bit Windows. In English that means that you should limit most PC’s to 3GB for now. The PC will work fine with the 4GB installed but will cause confusion when people can’t see 8it all reflected in windows.

For reference for the technical people – if this becomes an issue you need to look for machines with PAE (Physical address extension) support in the BIOS and generally a non-standard motherboard with extra pins for the processor (36 rather than 32). This in theory allows 64GB of RAM BUT can cause headaches with drivers (if they are hard coded to work with 32 bit addresses). Part of this is due to DEP (Data Execution Prevention) issues in windows.