Bootcamp/XP Ram Limitations
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- ********
Just upgraded my MBP to 4GB RAM. All installed fine. OSX sees all 4GB of RAM. When I boot into XP Pro under Bootcamp, I can see only 2.98GB RAM.
I have done some Google'ing and it appears that 3GB is the limit for XP on the MBP. Does anyone know if this is the definitive answer?
If I upgraded to Vista Business edition, would that allow me to see the full 4GB? Or do I HAVE to have a 64 bit version of either?
Thanks
- adev0
need the 64bit version to use all 4gb
- ********0
Hrm...so the 32 bit version of Vista won't cut it?
- Machuse0
no. its a mathematical limitation. with a 32 bit OS you can only address 3 or so gb of memory.
Its like running out of zipcodes or phone numbers - ip addresses even. The only solution is to add more numbers....hence 64bit.
32bit windows, has no way of giving more memory more unique addresses.- DogBreath just punched himself in the face.amongthemasses
- ********0
okey dokey. Thanks for that.
- airey0
i didn't think you could safely run anything but windows xp sp2. can you run vista now?
- ********0
I believe so...
- Mojo0
This is how it works:
32-bit windows has a max limit of 2GB allocated to your running applications. Windows also has 2GB for the kernel, and operating system stuff. You don't really get to use all of that, but by editing the boot.ini file and adding a /3GB switch, you can trick windows into letting you use 3GB for applications, and 1GB for kernel/OS.
I can't remember the exact details, but the upshot is that you can only use 3.5GB for applications. You can use something called Physical Address Extension (PAE) that is basically a dirty hack allowing old oracle server to use more RAM than allowed (performance issues).
Have a good ol' google for 'Windows RAM limits' or something. There are loads of articles about it.
If you want to use your RAM properly, get a 64-bit OS. I posted here about my experience with Windows XP x64 (great).