FreeBSD 6.0, amd64, A8N-SLI and 4gb ram

[Steve Kargl]

On Mon, Feb 13, 2006 at 10:03:55PM +1100, Robert Leftwich wrote:
> 
> I've been running FreeBSD 6.0 stable on an A8N-SLI Premium amd64 box
> with 2gb of ram for a few weeks now and it has been running well, but
> some of the analysis I run needs more ram, so I dropped in another 2 gb
> and started having all sorts of weird problems, such as DHCP failure and
> running very slowly. I tracked it down to 2 bios settings, both related
> to PAE (one turning on s/w PAE, the other h/w) - if i turn both of those
> off, then everything works, but FreeBSD can only see 3gb of ram. Some
> documentation suggested a custom kernel with 'options PAE'  enabled
> would be required, but adding that generates an 'invalid option PAE'
> error when running make. Is it possible for FreeBSD to access the full
> 4gb on this m/b?
> 

You don't need "option PAE" on FreeBSD-amd64.  If you have 4+GB,
then FreeBSD-amd64 should have access to the memory. 

We need to see the top portion of your dmesg concerning the 3 GB
versus 4 GB question.  This is a FAQ in that a small amount of
memory is reserved for the hardware/kernel. 

-- 
Steve