Memory >3.5GB not used?

[Bill Moran]

In response to "Jonathan Horne" <freebsd at dfwlp.com>:

> 
> > In response to "Don O'Neil" <lists at lizardhill.com>:
> >
> >> I just built a new server with an Athlon 64 x2, 4GB Ram and a
> >> Gigabyte/Nvidia motherboard.
> >>
> >> When I boot the system up it says on the console that 532888K will be
> >> ignored.
> >>
> >> Of course it isn't put in any of the log files. Dmesg shows this:
> >>
> >> real memory  = 3724476416 (3551 MB)
> >> avail memory = 3649908736 (3480 MB)
> >>
> >> Any reason the extra 1/2 GB isn't showing up or usable? Is there something I
> >> need to specify in the kernel to get to the other 1/2 GB? What if I want to
> >> install more than 4GB? This mobo supports up to 16 GB... Do I need to go to
> >> the AMD64 platform to get >4GB?
> >>
> >> I'm running FreeBSD 6.1 i386 SMP kernel.
> >
> > http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/troubleshoot.html#PAE
> >
> 
> i have a system with 4GB memory, doing the same similar behavior.  but, on top
> of not using the last few hundred megs of ram, even the POST shows like 3.6 or
> 3.7GB of ram.  is PAE still a solution for my case?
> 
> [jhorne at canopus ~]$ dmesg | grep memory
> real memory  = 3958833152 (3775 MB)
> avail memory = 3875762176 (3696 MB)

As noted in the FAQ, this is hardware-dependent.  Some crappy motherboards
don't remap the memory, and it can not be used as a result.

-- 
Bill Moran
http://www.potentialtech.com