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Re: 64 bit computers systems

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Josh Plummer wrote:
Bill Polhemus wrote:
"The chances of there being a single application that needs more than 4 GB of physical memory are pretty slim for the next decade or so."
That's a common misconception, Bill.  Yes, the OS handles the address space.  But, it's still going to limit how much memory a 32 bit program is allowed to use. 
 
That application's address space really isn't an issue, though. The OS handles that. The application doesn't care where it's loaded in memory just as long as it can play peacefully there.

The chances of there being a single application that needs more than 4 GB of physical memory are pretty slim for the next decade or so.
HOWEVER...

I would suspect that an application can be loaded into its own 4GB address space, the "virtual machijne" approach, and if you have a 64-bit OS, it will be able to set up several of those virtual machines for those 32-bit apps.

I guess I'm saying "you're right, if the application was compiled such that the variables cannot 'point' outside that 4GB address space, you're limited," but 4GB is a LOT of room for a single application to play with.


That said, your point about running out of RAM for a single application if you have a very demanding app is noted. You can't even get around it by saying "oh, I've got virtual memory to play with," because the 4GB limit is absolute. I suppose it can swap out, but that's still a bad solution.

I suspect within a decade or so, we'll all be using 64-bit systems for all they're worth.

(Gee, anybody remember when a SGI or IRIX or SUN workstation running *nix, with 32MEGA-Bytes of memory was considered the bleeding edge?)
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