Behind the 4GB Memory Limit In 32-Bit Windows

An anonymous reader points us to a very detailed post by Geoff Chappell, first put up early this year, explaining how the 4GB memory limit commonly bandied about for 32-bit Windows (he is writing mainly about Vista) is more of a licensing preference than an architectural limit. The article outlines how Chappell unlocked his system to use all the memory that is present, but cautions that such hackery is ill-advised for several reasons, including legal ones. "If you want [to be able to use more than 4GB in Vista] without contrivance, then pester Microsoft for an upgrade of the license data or at least for a credible, detailed reasoning of its policy for licensing your use of your computer's memory. ... [C]onsider Windows Server 2008. For the loader and kernel in Windows Vista SP1 (and, by the way, for the overwhelming majority of all executables), the corresponding executable in Windows Server 2008 is exactly the same, byte for byte. Yet Microsoft sells 32-bit Windows Server 2008 for use with as much as 64GB of memory. Does Microsoft really mean to say that when it re-badges these same executables as Windows Vista SP1, they suddenly acquire an architectural limit of 4GB? Or is it that a driver for Windows Server 2008 is safe for using with memory above 4GB as long as you don't let it interact with the identical executables from Windows Vista SP1?"

Comments

Re:On 32 bit WinXP, you can't even use 4 GB

[geekoid]

2GB per APP. not total.

Re:Wa wa what?

[Spy der Mann]

In other words, Windows is bona fide crippleware.

Can that be modded redundant? :P

Re:Let's just get over this and move to 64bit

[GreatBunzinni]

You failed to understand that re-purchasing a vast set of licenses for some 64-bit OS just for the sake of it being 64-bit when your entire portfolio of applications and hardware (you need drivers) was built for the 32-bit platform... Well, it doesn't make any sense. It means that you intended to migrate your office from a 32-bit OS to a 64-bit OS without any other justification beyond "I felt like it", which carries a hefty price tag and absolutely no technical justification.

And moreover, the claims that 32-bit apps "just run fine on 64-bit windows" are made from the same people who claimed that your Windows XP apps "just run fine on Windows Vista" and we saw how that panned out.