I haven't been on bit-tech for awhile but now I need you people again... I am planning on installing 4 x 1GB sticks of RAM into my machine and I heard that Windows XP Pro will only show 3GB of it. I know why it does but, what I'm here for is to know if it still can use ALL of my total physical ram. Because people tell me that XP only "SHOWS" 3GB... but they never tell me if it could use all 4GB of it.
Its a limitation of 32bits OS-ses. Not just WinXP Home, but Pro also, and W2K has the same limit. There's a way to be able to access all 4 GB's. You need to change a boot parameter in boot.ini, but i cant remember what parameter you should add... guess google has the answer to that...
I was looking around and found these... /3gb /userva=2900 or /PAE any of these? I'm confused, couple people tell me I dont need to edit anything and some people say I do.
You will only ever be able to use the full four gigabytes with Windows XP 64-bit edition. The maximum addressable limit of any 32-bit operating system is 2^32 bytes, or about 4GB. However, much of this is actually reserved. Modern computer systems use a technique called memory-mapped I/O, whereby CPU-addressable memory space is actually reserved as a means of communicating with I/O devices. These devices monitor the CPU's address bus and direct any operations performed on the MMIO area to their registers, effectively remapping the section into peripheral memory. To save time and money, it is not actually possible to bank switch this area between memory and device addresses, so it's effectively unusable. However, if you're running a 64-bit processor and operating system, you can activate an option in your BIOS (usually PCI MMIO remapping or Remap Memory Hole Above 4G) that moves this MMIO area above 4GB to allow you to use the complete RAM capacity (note that you can activate this option without running a 64-bit OS, but it probably won't do anything). There is a way to enable access to a bit more than normal on XP by modifying some configuration data (AFAIK it's the /PAE (physical address extension) switch), but ultimately you will never be able to access all of it unless you switch to XP64 or an equivalent Linux distribution.
It shouldn't cause any issues. I'd take a backup of boot.ini just so that you can easily copy it back from a command prompt just in case, though.
