# PCI Controller to breach 137GB Barrier



## pateln (Oct 24, 2010)

I'm preparing to install FreeBSD 8.1 on a HP KAYAK xu800 workstation with a large PATA array using zfs; however, I realized that the workstation is restricted by the 28bit/137GB addressing barrier.

I need to find two IDE PCI controller cards to accommodate the HDD array, and since I've never used one I'm looking for advice/"heads up" on issues I might run into.

I'm building on a budget, so I've found two inexpensive cards:
Adaptec ASH-1233 Ultra ATA Adapter - I believe this runs on the Silicone Images SiL0680 chipset

Promise Ultra 133 TX2 IDE controller - This runs on a promise chipset obviously, as do some other popular cards I'm looking at (I think Maxtor makes one)

Should I expect any problems when installing these cards?  Which driver does each card use?

Also- if I'm building a "RAID10" zpool, should I avoid mirroring two drives across different cards?  I would like to maximize the redundancy of the array, and mirroring drives across cards seems to prevent array failure from a single card failing.


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## jem (Oct 25, 2010)

The Promise Ultra133 TX2 works fine with FreeBSD, but don't expect it to be fast.  The PCI bus will be a bottleneck, although this card will take advantage of a 66MHz PCI slot if your system has one.

When I first started playing with ZFS I set up a three-disk raidz pool using PATA disks.  One disk was on the secondary master motherboard channel and the other two were masters on the two Promise channels.  I got less than 10MB/s write rates to the pool, but this was an ancient creaky old Athlon XP box.


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