How to debug >2GB memory issues (and 3ware)

[James R. Van Artsalen]

John-Mark Gurney wrote:

>Not sure about 2GB, since that seems like someone is handling a
>signed value incorrectly or something like that, but there is the
>busdma status page at:
>http://www.freebsd.org/projects/busdma/
>  
>
twe works for me if hw.physmem is set to 3G in my 8GB RAM system.

twe works with 8GB of RAM in 5.2.1.

Both the twe driver and busdma have changed since 5.2.1.  Since ATA is 
also rumored to be unreliable with more than 4 GB of RAM in 5.3 I would 
not ignore that the possibility of a problem in busdma.