> > 1. What is the maximum amount of RAM that Linux supports in the various
> > architectures? Where is this information defined/stored?
>
> The maximum is (as far as I know) 1GB on x86 (must specify mem=...
> above 64MB), probably much more (64-bit addresses) on the Alpha.
As implemented Linux/MIPS supports 512mb physical RAM and 2GB virtual
address space per user process. This will also stay the limit for the
32 bit processors (R2000/R3000/R6000 families). For the newer, 64 bit
architectures (R4000/R4400/R4600/R8000/R10000/R5000 and the numerous
derivates) those limits can be raised to 0.5TB, maybe 1TB virtual
address space per user process.
For the current implementations the absolute limits are the 36 bits
address bus (== 64GB) and 1TB virtual addrss space for user programs. This
shouldn't really be a limit for anyone (no, don't mmap your TB raid array ...)
but iff there is room in the architecture to grow the user address space up
to 2^63 bytes (8 Exabytes), the physical address space up to 2^56 bytes (64
Petabytes). Numbers that are pretty insane huge ...
Ralf