AHCI driver

[Dick Hoogendijk]

  I'm told it would be better to enable the AHCI driver form my SATA2 
drives. It would make ZFS perform better on them. From the release notes 
I get:

FreeBSD cam(3) 
<http://www.FreeBSD.org/cgi/man.cgi?query=cam&sektion=3&manpath=FreeBSD+8.1-RELEASE> 
SCSI framework has been improved and a new kernel option |option 
ATA_CAM| has been added. This turns ata(4) 
<http://www.FreeBSD.org/cgi/man.cgi?query=ata&sektion=4&manpath=FreeBSD+8.1-RELEASE> 
controller drivers into cam(4) 
<http://www.FreeBSD.org/cgi/man.cgi?query=cam&sektion=4&manpath=FreeBSD+8.1-RELEASE> 
interface modules. When enabled, this option deprecates all ata(4) 
<http://www.FreeBSD.org/cgi/man.cgi?query=ata&sektion=4&manpath=FreeBSD+8.1-RELEASE> 
peripheral drivers and interfaces such as ad and acd, and allows cam(4) 
<http://www.FreeBSD.org/cgi/man.cgi?query=cam&sektion=4&manpath=FreeBSD+8.1-RELEASE> 
drivers ada, and cd and interfaces to be natively used instead. Note 
that this is not enabled by default in the GENERIC kernel.

Is it really better to enable AHCI driver?

Will I be able to GEOM label normal disks (like /dev/ad0) or do I need 
/dev/ada0 drives for that?

Thanks for any help / advice on this matter. I'm building the server and 
want to do things right from the start.