32-bit OS and RAM issues

[Tickmeoff]

Let me first say that I am fully aware the maximum amount of RAM a 32-bit OS can read is 4096 MB.

Since I built this computer earlier this year I have been running 2 GB of RAM and haven't had any issues, but I found a nice deal on Black Friday and ended up obtaining another 5 GB. I have 32-bit versions of both XP Pro and Vista Ultimate, so I fully expected I would have to upgrade to 64-bit to utilize all this RAM (if I even have anything that will come near utilizing all of it), but then I saw this in Vista:



So now I am a little confused. As far as I know Vista should not be reporting more than ~3 GB of RAM. XP is only reporting about 3 GB, so I am not really sure what's up. I googled it a bit but wasn't able to find anything, and either way with a 32-bit OS it should be mathematically impossible for it to read all 7 GB of RAM. Does anyone here know something I don't?

[Mhurron]

Vista supports up to 8GB

(32bit Windows Server 2003 supports up to 64GB)

Physical Address Extension - Wikipedia, the free encyclopedia

And yes, people know things you don't.

[KingOfZeal]

Mhurron is correct. I had done some research on it after I put 4 gigs into my laptop, and it was only registering 3.5 (not a big difference, sure, but I want my money worth). The main reason that a modern (but 32 bit) system sometimes won't recognize over 3 gigs has to do with the memory addressing system -- addresses that would logically be used for everything after 3 gigs is used for hardware bus systems. Or something like that. But, iirc many of the modern motherboards, which are supposed to support over 3 gigs, basically re-address the memory over ~3.5 gigs so the system can use it... kinda like how the P4s with HT, while they didn't have 2 physical cores, still registered as a duel-core system.