It's written in a comment that this 3GB limit is a Windows limit, so maybe it's from the the Win9x memory layout (http://support.microsoft.com/kb/q125691/). I don't know why the 3GB would be special in the NT memory layout. I would need to check that but I think we can change this in NT mode. It would be best to take the vmsplit value from the kernel, but I don't know yet how it can be queried at runtime. > > Windows XP x86 will not use the full 4GB (as a total address space for > all processes) even if PAE is enabled since Service Pack 2... > It's getting a bit off-topis, but AFAIK the PAE was enabled in SP2 only because it is required to use the NX bit (no-execute memory, a.k.a. XD, DEP). To have true PAE support you need to have Windows Server Enterprise (or a 64-bit OS).
