THE END Posted March 26, 2008 Share Posted March 26, 2008 why does windows XP show my 4GB ram as 3.25 GB RAM Physical Address Extension? http://i15.ahpic.com/yb3xl9.png Link to comment Share on other sites More sharing options...
Lighthalzen Posted March 26, 2008 Share Posted March 26, 2008 It is a limitation of 32-Bits OS, upgrade to 64-Bits if you want to see all 4GB of your RAM. or... Windows 2003 Standard Edition (32-Bits) http://www.microsoft.com/whdc/system/platf...PAE/PAEmem.mspx Link to comment Share on other sites More sharing options...
Chicane-UK Veteran Posted March 26, 2008 Veteran Share Posted March 26, 2008 Strange. According to that link, XP should understand PAE and should allow you to see all 4GB of your RAM... Link to comment Share on other sites More sharing options...
Lighthalzen Posted March 26, 2008 Share Posted March 26, 2008 Doesn't work all the time cause all the hardware have to match up or something like that. Someone said it the forum once, and this have been posted like so many many times, lol. Link to comment Share on other sites More sharing options...
THE END Posted March 26, 2008 Author Share Posted March 26, 2008 so my 4 GB ram is not being being used? is it the same case in VISTA 32bit as well? Link to comment Share on other sites More sharing options...
Antaris Veteran Posted March 26, 2008 Veteran Share Posted March 26, 2008 Windows XP supports a 4GB address-space, you shouldn't be getting this confused with RAM. Address-space is used to address everything from RAM, the System ROM, APIC(s), PCI devices etc. What this means is that your copy of XP is allowing 3.25GB of the appropriate address-space to be reserved for addressing RAM, and the remaining address space is mapped for other uses. The next thing you are probably wondering is why this doesn't happen when you have less RAM? Well, the answer is short: At startup, the BIOS determines the hardware components that require address space and calculate how much is required for the system. This is then subtracted from the 4GB maximum, and the remainder is allocated to RAM. If there is less RAM then the allocation, then all the RAM is available to the system. Hope that clears things up. Link to comment Share on other sites More sharing options...
THE END Posted March 26, 2008 Author Share Posted March 26, 2008 so its a good thing that system has got pre allocated ram. yeah? Link to comment Share on other sites More sharing options...
AltecXP Posted March 26, 2008 Share Posted March 26, 2008 so my 4 GB ram is not being being used? is it the same case in VISTA 32bit as well? Its the case in all 32-bit OS's. I never got how people think this is a MS thing. Link to comment Share on other sites More sharing options...
Jason S. Global Moderator Posted March 26, 2008 Global Moderator Share Posted March 26, 2008 ive read about the PAE and it's supposed to allow all 4GB to be used under 32-bit. idk the requirements to make this work though. anyone know? Link to comment Share on other sites More sharing options...
Antaris Veteran Posted March 26, 2008 Veteran Share Posted March 26, 2008 PAE allows the system to support more than 4GB of RAM not address-space in a 32-bit system. The available addressing space in XP x86 is still only 4GB, so the allocation i mentioned earlier will still apply. Link to comment Share on other sites More sharing options...
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