Re: debian-user] Re: AMD vs Intel and the Debian kernel

[Daniel Burrows <dburrows@debian.org>]

On Mon, Aug 18, 2008 at 07:14:43PM -0700, Daniel Burrows <dburrows@debian.org> was heard to say:
>   The good news is that if you have a 64-bit processor, the
> amount of memory you can install is limited only by the amount your
> motherboard can recognize.  Also, memory is super-cheap nowadays.  So
> if you have 8 virtual machines and you want each to have access to a
> gigabyte of memory, throw 8GB in on top of what the host system needs
> and you should be good.

  Just to pedantically correct myself:

  Of course, even with a 64-bit processor, there is a limit to how much
memory you can address.  Specifically, just as the hard limit for a
32-bit processor is 2**32, the hard limit for a 64-bit processor is 2**64.

  But that's approximately 2**34 gigabytes, and the lowest
price-per-gigabyte that I can find for RAM chips is about $20.  So to
max out a 64-bit memory space, you would need to spend around

     $343,597,383,680

  , or about $350 billion dollars.  And before you even got there you'd
have to worry about chips failing, heat dissipation issues, cosmic rays,
etc etc.  Not to mention that I doubt any current motherboards accept
anywhere near that much RAM.

  So you don't need to worry about this any time in the foreseeable
future. :-)

  Daniel