4 gig problem

I had bought extra RAM for the box , upping total to 4 gigs.

I install the chips , boot up Vista and check under “My Computer-> Properties” and it shows 4gigs. So , chips are ok and everything’s cool.

Week passes by , I’m try to run multiple VMs and seem to run into a performance snag .

So , I start the windoze troubleshooting ritual by opening up task manager. So here comes the funny part , it shows 2.5 gigs of physical memory ? But “My Computer-> Properties” shows 4gigs ?

After reading up forum posts on this , here is what I understood.

1> My Computer –> Properties shows you the physical memory present on the box.

2> Task manager will show you the physical memory that is actually getting used by Vista.

3> PAE is disabled in Vista (PAE lets 32 bit windoze OS’s go above the 4GB barrier)

4 If you have 4gigs , then this formula applies : Memory that can be used by Vista = 4GB – Graphic Card RAM (1 gig in my 8600GT) – Some RAM used by BIOS (~ 300 MB)

So , don’t go to 4GB on Vista 32bit , 3GB should be okay . Or install 64bit Vista (that’s what I did )