Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

uMac

macrumors 6502
Original poster
Mar 27, 2007
250
0
Canada
I've installed XP Home on my Mac Pro and after the Install everything is running fine except the computer cannot see all the ram I have (I think it only sees the first chip)

Suggestions?
 

weg

macrumors 6502a
Mar 29, 2004
888
0
nj
2^32 = 4.29GB, so the max is 4GB

Theoretically, yes, but a large part of the 4GB is reserved for the operating system, so there are only 2GB available for the applications. He'll need the 64bit version of Windows XP or Vista 64.
 

CanadaRAM

macrumors G5
32 bit Windows can theoretically address up to 4 GB BUT hardware addressing limitations mean that the total available to the OS is somewhere between 3.0 and 3.5 GB. On a PC, Windows itself will report 3 GB available (the space above 3 GB is used for drivers and resources), and the most available to a single application is 2 GB.

Under Bootcamp, 32 bit Windows is restricted to 2 GB RAM regardless how much extra is in the Mac. This is an issue with the Mac's firmware/EFI. Scattered people have reported seeing 3 GB on MacBook Pros, but it is unclear whether this is an artifact of the Windows utility used to report the RAM size or not. (The addressable RAM is not affected by the /3GB and /PAE switches in Windows, as meny have posted without trying it -- these are for allocation of memory to applications within Windows.)
 

fuzzielitlpanda

macrumors 6502a
Mar 24, 2008
834
0
32 bit versions of windows will see only up to 3gb of ram. if you plan on installing anything greater than that, run a 64 bit version.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.