Venus T4S eSATA Enclosure by American Media Systems

I picked up this unit at Frys for $179. Looked like a great way to add an external RAID 5 drive bay to my Mac Pro.

Unpacked box, installed four Western Digital 750GB Drives. This unit comes with a PCIe x1 SATA Controller card based on the
Silicon Image 3132 chipset. Installed card and went to get OS X drivers.

This is where the fun started.

On the Silicon Image and American Media websites, they both offer the following drivers.

1) SiI 3132 32-bit universal Mac OS X 10.4.x BASE Driver (Version 1.1.9) Dated 12/26/2006
2) SiI 3132 32-bit universal Mac OS X 10.4.x SATARAID5 Driver (Version Dated 8/14/2007

My plan was to use Raid 5 to get 2.25TB of useable space out of 3TB of drives. I installed the RAID 5 Driver and software shown as number 2. Install went fine, was able to see all the drives, created the RAID 5 array and initialized. This took about 6 hours.

Then the real joy started. I formated the array and proceeded to copy my photo store to it. I copied about 4 Gigs before everything went to hell. At about the 4GB point, data copy just stopped and the machine became somewhat unstable. My first response was to try to reboot the enclosure to figure out what was going on. Doing this caused the enclosure to freak out. The power light would just flash on and off and the drives would not spin up (Story below about this). Once the unit was back online, tried again, keep having the same system lookup issues. Well the moral of this story is that the supposed "Universal" Raid drivers and software run as PowerPC processes. Hardly universal. As you can imagine trying to run a RAID controller via Rosetta is not something you want to do. I am amazed it worked at all.

So, I went to the first driver listed above. This works great with OS X, but provides no RAID 5 support. The RAID 5 software now says no controller installed. But now OS X Disk Utility sees the drives. I can now create two 750GB Mirrors. This isn't the 2.25TB RAID 5 Array I wanted, but whatever 1.5GB is doable for the price of this unit. This configuration worked well for about a day as I was copying my files over. If the Mac is awake and the drives in the enclosure go to sleep, I click on a disk on my desktop and it spins up the two drives in that mirror, it works great.

HOWEVER.. If the Mac goes to sleep and I wake it up, it kicks power to all drives, this causes all four to spin up while the enclosure is warm. This results in the unit failing with the blinking power light and of course OS X freaks out wondering where the drives are.

Long story short, what is going on here is the 120W power supply is underpowered for this case. I went back to Frys and picked up a second unit. Same problem. Basically, with all four drive bays full, the unit powers up just fine if cold. However if the unit has been running for over 20 minutes or so, the unit will not power up with all drives. You either have to wait around 10 minutes for the Power Supply to cool down or pull one of the drives. The unit will power up just fine with 3 or less drives when warm. Then you can plug the forth drive back in. This is simply unacceptable for me. I looked into the settings of the onboard controller in the case for a delayed power up option to stagger drive spin up. No such setting exists on this device.

Summary - This unit is underpowered for four drives. It works great with 2-3 drives. However it advertises four drive support, I had no desire for a 2-3 drive enclosure. It's still a decent price for a 2 drive RAID 0 or 1 setup as it includes the card. It's a cheap card and cheap enclosure and gets the job done with 2-3 drives. That said, it should support four and I am returning the unit.

Pros -

Cheap 2-3 Drive RAID O or RAID 1 setup. Card driver install is easy and quick, works great with Disk Utility.

Small nice looking unit, extremely quiet.

Cons -

Underpowered for four drives.

RAID 5 Support does not work on Mac Pro with Intel Procs. Should work fine on G5 based systems.