I have seen a ton of debates over whether or not 32-bit XP can address 4GB or not recently. They talked about it on ExtremeTech, on DL.TV, and a few other places. If I remember correctly, there is a way to get XP to display all 4GB but as was pointed out by Bobby you can't actually use all 4 GB.
As far as the question about a RAM drive, if Windows can't access the physical RAM then you would have to have some program make the RAM drive before Windows starts up, I don't think you could do it from within Windows.. And of course there is also the question of whether your BIOS supports more than 4 GB. Some do, some don't. ----- Brian Weeden Technical Consultant Secure World Foundation On Sat, Mar 8, 2008 at 9:10 AM, Bobby Heid <[EMAIL PROTECTED]> wrote: > I don't think so. 32-bit OSes can only address 4GB RAM. The thing is > that > your video card RAM, BIOS, etc have to map into that 4GB address space > also. > That is why you lose approx 750MB RAM when you have 4GB. The RAM is still > there, it is just not addressed. > > Kind of like this: > > Physical RAM Memory Mapping > |----- 4GB |----- 4.00GB > | | Graphics card memory, > BIOS, > etc. > | |----- 3.25GB > | | > | | > | | > | | > | | > | | > | | > > Bobby > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Thane Sherrington > Sent: Saturday, March 08, 2008 8:11 AM > To: [email protected] > Subject: Re: [H] RAM ceiling 3.25GB ...maybe not > > At 04:15 AM 08/03/2008, Winterlight wrote: > > >This is in this months Maximum PC page 23 sidebar. > > > >------------------------------------------- > >Our RAM configuration isn't that simple, though. Although the board > >posts just fine with 4GB, running a 32-bit windows OS doesn't quite > >give you full access to the RAM. Check Windows XP and it'll report > >only 3.25GB free. So is the other .75GB wasted? Not quite. It's a > >complicated issue, but Microsoft argues that even if the > >applications cannot use all 4GB of RAM, the OS, and even the > >drivers, will, so the additional headroom does help. > >------------------------------------------- > > Side question on this. If I had 8GB of RAM, and 32 bit XP, could I > create a 5GB RAM drive, and use it for temp and swap files while > still using the other 3GB for Windows? Wouldn't that give me, in > effect, the advantage of 8GB of RAM since I'd be paging at RAM speed? > > T > > > >
