PCI-X SATA Card + Server Recommendation

[Danny Carroll]

Jeremy Chadwick wrote:
> These are cards I can recommend for your situation.  Yes, they do RAID,
> they all support JBOD; just plug the disks in and go.
> 
> http://www.highpoint-tech.com/USA/series_2000.htm
> HighPoint RocketRAID 2210  (hptrr(4) driver; be sure to read NOTES)
> HighPoint RocketRAID 2220  (hptrr(4) driver; be sure to read NOTES)
> HighPoint RocketRAID 2224  (hptrr(4) driver; be sure to read NOTES)
> HighPoint RocketRAID 2240  (hptrr(4) driver; be sure to read NOTES)
> 
> http://www.areca.com.tw/products/pcix.htm
> Areca ARC-1110    (arcmsr(4) driver)
> Areca ARC-1120    (arcmsr(4) driver)
> Areca ARC-1130    (arcmsr(4) driver)
> Areca ARC-1160    (arcmsr(4) driver)
> Areca ARC-1130ML  (arcmsr(4) driver)
> Areca ARC-1160ML  (arcmsr(4) driver)

One other thing that those in the know might be able to answer for me.
When thinking about ZFS or Geom (or even vinum!) and a decent SATA card
in JBOD mode:

What happens with the write caching?   Do the caches only work when you
build an array?   If they also work in JBOD mode, then I guess it is
important to disable all write caching (can you even do that with these
cards?) unless you also buy the BBU?

I'd be interested to know for sure so I know if I must shell out for a
BBU as well as the card itself....

-D