This screenshot was taken with 1.09C BIOS. The hardware reserved amount is slightly different.
But with 1.10c you should have the same amount like other users with Pi 3525.
EDIT: you have Pi3540
That's probably the reason why you see slightly different values.
The other MSI notebook you're talking about probably has a 'real' graphic card (ATI/nVidia) with dedicated video RAM.
Amilo Pi 3525 Eclipse black, 4096 MB RAM, Penryn-3M core P7350 (2.0 GHz, 1066MHz FSB, 3MB L2 cache) / OpenSolaris 2009.06 / Ubuntu 10.04.04