Can 32bit WinServer2003 use more RAM than XP32bit?

Yes, all 32-bit systems have the same memory limitations execpt for Enterprise which still has the physical memory limitations but the OS is configured to use the higher memory allocation. 32-bit systems don't manage memory very well at all.

Hi brettr,

32-bit systems have the same, however 32-bit systems don't control memory all that well.

@dariusg

What do you mean by

>>Enterprise...but the OS is configured to use the higher memory allocation<<

Server 2003/2008 Enterprise editions support more then 4 GB but you must place the /PAE switch in the boot.ini to see the rest of the memory because 32-bit systems have a limit of 4 GB. Even if you have 4 GB in a system you might only see 3 GB because the system takes some memory for itself to see the rest you must use the /PAE switch in the boot.ini.

"... Does the 32bit version of Windows Server 2003 have the exact same memory cap as Windows XP 32bit? " ==>  As asked, the answer is no -- it's not the "exact same" cap, as Server allocates some of the interrupt vectoring and shadowing slightly differently.   But it is exactly the same concept => all 32 bit OS's have to allocate addresses for system-level functions (PCI addressing; interrupt tables; AGP aperture; BIOS shadowing; video addressing; etc.) and these are allocated from the top of the 4GB address space downwards.   Whatever's left after those are assigned is what can be allocated to your physical RAM.   You'll typically "see" about 3.2 - 3.6GB with 4GB installed => the exact amount depends on the specific system configuration.   With a typical server, it's likely to be at the upper end of that range, as it most likely does not have a high-end video card with a lot of VRAM.

Vista x32 has the same restrictions, although with SP1 it will "show" a full 4GB if you check the system properties page on most chipsets (You can see the actual allocations in Device Manager;  note also that on some chipsets Vista won't show the full 4GB).

Server 2003 Standard has the 4GB limit; but the Enterprise and Datacenter Editions can address a lot more.   The specific caps depend on whether you're using the /3GB switch, but they can address either 32GB (Enterprise),  64GB (Enterprise R2), 128GB (Datacenter), or 16GB (all 3 of these versions with /3GB switch).   As indicated already, they do this by using an extended page address mechanism implemented through the /PAE switch.

Can a 32 bit machine fully utilize a 64 bit OS?

No, you can't install 64-bit on 32-bit software.