Re: [Hampshire] 64 bit graphics drivers

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Author: Brad Rogers
Date:  
To: hampshire
Subject: Re: [Hampshire] 64 bit graphics drivers

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gpg: failed to create temporary file '/var/lib/lurker/.#lk0x57334100.hantslug.org.uk.12436': Permission denied
gpg: keyblock resource '/var/lib/lurker/pubring.gpg': Permission denied
gpg: Signature made Sat Apr 5 15:12:48 2008 BST
gpg: using DSA key 497BD1F48AB6137F
gpg: Can't check signature: No public key
On Sat, 5 Apr 2008 14:31:35 +0100
"Rob Malpass" <rd.malpass@???> wrote:

Hello Rob,

> 1) I want to build a machine with a lot of RAM for virtualisation (I
> want to run a handful of servers on one physical box) purposes -
> probably 8Gb - the maximum the board supports. However I'm told I
> can't get at all of this RAM unless I run in 64 bit mode. Is this
> true?


Seems about right to me. It's all a matter of how big a number a
processor can handle. With a 32 bit address bus, the largest unsigned
number that can be written is 4,294,967,295 or 4Gig. With a 64 bit
bus, that number increases to 18,446,744,073,709,551,615. IOW, much,
*much* bigger.

You can try and stick 8 Gig into a 32bit machine (or machine running in
32bit mode), but you'll never use all of it, since if you add 1 to
4,294,967,295 you get 0. That is, you'd overwrite existing data and
the machine shouldn't allow that to happen.

All this applies to a single processor machine, of course. Start
parallelling CPUs, and all sorts of things can be done.

-- 
 Regards  _
         / )           "The blindingly obvious is
        / _)rad        never immediately apparent"


Now I found you out, I don't think you're so smart
Who Are You - Black Sabbath