Windows XP RAM limitation

**Starks** · February 21st, 2012

The 4GB limit for 32-bit also includes VRAM of your video card

**Perkins** · February 21st, 2012

http://www.geoffchappell.com/notes/w...nse/memory.htm

PAE is already enabled by default because they use it for their DEP algorithms. Logically any driver coded to understand PAE addressing should be good with it, regardless of how much memory is actually present, while drivers that are incompatible with it will be incompatible even if only a lesser amount of memory is being used. Plus drivers that need to touch the memory directly are generally the kinds of drivers that both Microsoft and the hardware manufacturer test thoroughly. Plus they support >4Gb on Windows 2000. Which is older than XP. Disabling use of > 4Gb by default for paranoia reasons so that the average user's system will just work out of the box I could understand. Locking it out so that nobody can use it, even at their own risk, is fairly obviously a contrivance to sell 64-bit versions of their operating systems. Especially when they phrase things to make it sound like a 32-bit limitation and not a Windows limitation.

**mister_playboy** · February 27th, 2012

In looking at a 64-bit Windows install, you may find 98% of the programs are actually 32-bit. Even core system stuff like IE will run as 32-bit by default.

It will be many years before they really transition over, and even then it will probably only be forced by MS releasing a 64-bit only OS.

**leclerc65** · February 27th, 2012

I've been running 64-bit linux for years now and there are no issues.

I planned to go 64-bit with Ubuntu 12.04. Can you tell me whether a 64-bit distro can run 'virtualboxed' 32-bit XP ?
The last and only time I tried 64-bit is 9.04 (I think), Truecrypt didn't even open my truecrypt volume.

**Perkins** · February 28th, 2012

Theoretically, as long as the processor supports the operating system you're trying to install as a guest, it should work just fine to install a 32 bit guest inside a 64 bit OS. It doesn't work the other way around though.

**CharlesA** · February 28th, 2012

Originally Posted by Perkins

Theoretically, as long as the processor supports the operating system you're trying to install as a guest, it should work just fine to install a 32 bit guest inside a 64 bit OS. It doesn't work the other way around though.

Installing a 64-bit guest on a 32-bit host only works if you have hardware virtualization enabled in the BIOS and your CPU supports it.

I've never tested it personally because I only run 64-bit OSes.

**Perkins** · February 28th, 2012

I have a 64 bit processor with hardware virtualization running a 32 bit os, and virtualbox at least won't boot a 64 bit kernel in it. Of course, I'm a few versions back on virtualbox, so that could have been updated.

Some other VM program might do it though.