32 bit OS - 3 gig memory limit?

[imbezol]

Ok, so this isn't Linux specific but I wanted to mention it anyways since it was interesting. Snotrocket actually brought this up in #crd today by telling us why he could only see 2.5 gigs on his 4 gig system. Everyone in the channel thought he was obviously doing something wrong until we did a little google work.

When you are running a 32 bit operating system you are limited to 4 gigs of memory. However, that 4 gigs of address space that 32 bit OSes have is also used to map the video card memory, sound card memory, raid card memory, etc. So if you have 4 gigs of ram in your system but you have a pair of 512mb video cards, you're going to have less than 3 gigs of usable ram.

How can you get around this? Well, with a 32 bit OS, you can't. The only way to use all your memory is to upgrade to a 64 bit OS.

For further reading, here's a good link on the issue:
http://www.dansdata.com/askdan00015.htm

[fydo]

Snotrockt is obviously doing it wrong.