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Date: Thu, 17 Nov 2005 14:27:34 -0600
From: Dan Nelson <dnelson@allantgroup.com>
To: Chuck Swiger <cswiger@mac.com>
Message-ID: <20051117202734.GF62141@dan.emsphone.com>
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Cc: "Marc G. Fournier" <scrappy@hub.org>, freebsd-questions@freebsd.org
Subject: Re: EM64T supported?
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In the last episode (Nov 17), Chuck Swiger said:
> Marc G. Fournier wrote:
> >First off, what is it?  On 32bit platforms, to address >4G of RAM, I
> >recall that there is some sort of 'paging' that has to be done to
> >address it ... does EM64T get around that somehow, or is this just
> >another name for it?
> 
> EM64T uses 64-bit wide registers and addressing, and can talk to >4GB
> of RAM natively.  Older processors may still support >4GB of physical
> RAM using the PSE/PSE-36 CPU extensions, but are still using 32-bit
> registers.

PAE/PAE36, right?  Note that if you enable PAE, some drivers may not be
available.  See the PAE kernel config file for a list.

-- 
	Dan Nelson
	dnelson@allantgroup.com