Re: > 1GB RAM on x86 ?

Jakub Jelinek (jj@sunsite.ms.mff.cuni.cz)
Thu, 3 Jul 1997 18:41:39 +0200 (MET DST)

> We're testing some x86 systems with more than 1GB of RAM. Linux on
> x86 seems to be limited to 1GB of physical memory. This suprised me a
> bit since I thought 386 PTE's had 20 bits for physical page addresses
> (4GB physical). Is there a 1GB physical limit, what's the reason for
> the limit, and what would need to change to increase this to 4GB?
> (i.e. Where did those other 2 bits go?)
>
> I also seem to be seeing a limit on swap space of 1GB. What about
> increasing that too?

If you need that much memory, I think it is not non-sense to spend much less
money than you give for memory chips in upgrading to a real CPU (64bit) also.
Even on an Ultra-I you get the physical RAM limit 1TB (and another
one for IO space) and Linux actually supports that.

Cheers,
Jakub
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Jakub Jelinek | jj@sunsite.mff.cuni.cz | http://sunsite.mff.cuni.cz
Administrator of SunSITE Czech Republic, MFF, Charles University
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Ultralinux - first 64bit OS to take full power from the UltraSparc
Linux version 2.1.44 on a sparc64 machine (333.41 BogoMips).
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