Wolf Paulus

Posted by Wolf Paulus on Jan 6, 2008 in Hardware

Replacing the PowerMac G5 with a Mac Mini (Core-2-Duo) has worked out great so far; I really do enjoy this small, fast, and quiet computer. However, to put Mac OS X Leopard’s new integrated backup program a.k.a Time Machine to work, requires a 2nd harddrive. Luckily, I had removed the secondary harddrive, which we had added just a couple months ago, from the PowerMac, before selling it and finding a nice external enclosure for the 3.5″ SATA drive shouldn’t be all that hard.

Acomdata Samba USB Enclosure Kit Black

The harddrive at hand is a 250B Seagate ST3250823AS, a pretty regular 7200 RPM drive with 8MByte buffer – the spec. is available here:

http://www.seagate.com/support/disc/manuals/sata/cuda72008_sata_pm.pdf.
After looking around for a while, I finally settled on the black acomdata samba hard drive enclosure, which supports both 3.5″ SATA or PATA drives.

It’s a fanless enclosure but has air vents on front and back; it comes with a shielding cage, an important feature, not to be found in really cheap enclosures. Most importantly however, the acomdata 701 Samba Hard Drive Enclosure comes with one of the better power supplies: a 12V 2A AC wall-adapter. Most of the 3.5″ hard drive enclosures that are in the Samba’s price range come with really cheap dual voltage (12V 5V 1.5A) AC adapters, the ones with the S-Video style connector.
Taking a closer look at the aforementioned Seagate SATA drive spec reveals that the drive requires a startup current of 12V 2.8 amps, which even the Samba just barely provides. However, cheaper enclosures like the POWMAX 3.5″ eSATA USB2.0 EMVESAT35 (a.k.a Moving Star) for instance aren’t able to start the drive half the time.

Putting the spare 3.5″ SATA hard drive we had laying around, into a nice external enclosure, was easy and economically the right thing to do. Above, we pointed out the importance of looking at the drive’s power requirements and comparing that with the enclosure’s power supply parameters. One week back in service again, the now nicely enclosed Seagate ST3250823AS SATA drive has been working great so far and is used by Mac OS X Leopard’s new integrated backup program a.k.a Time Machine.

I really like the looks of the black Acomdata Samba USB Enclosure but it’s kind of big, considering that sits right next to a Mac Mini. Also, the required 12V AC wall-adapter makes this a pretty much stationary device, not suited for moving around a lot.

LaCie Portable Hard Drive
Instead, a really cool and portable external hard drive is the LaCie 160 GB USB 2.0 Portable Hard Drive. The compact (3 x .65 x 5 in / 76 x 17 x 129 mm ) and very lightweight (6.35 oz / 180 g ) device houses a 2.5″ 5400 rpm hard drive. This is arguably the best looking external drive but what’s even better is that there is also a FireWire 400 (up to 35-40MB/s) version available.

External Harddrives File Transfer Speeds Compared:

USB 2 vs. Firewire 400

After reviewing the Acomdata Samba USB Enclosure, which houses a Seagate SATA 3.5″ 7200 RPM drive with 8MByte buffer, and also the LaCie 160 GB Portable Firewire-400 2.5″ 5400 RPM drive a couple weeks ago, I finally took the time to run some simple file transfer speed tests on both drives.

USB 2: SATA 3.5″ 7200 RPM vs. FireWire-400: 2.5″ 5400 RPM

Single file [200 MB]

3750 files [combined 22.2 MB]

• Internal Drive: Hitachi Travelstar HTS541612J9SA00
• External USB: Acomdata Samba USB Enclosure / Seagate ST3250823AS SATA
• External Firewire 400: LaCie 160 GB USB 2.0 /Firewire400 Portable Hard Drive

Results

Setting the observed time to copy files to and from the USB drive to 100%, means that reading from the Firewire drive is about 6% faster for a single larger file and 10% faster for a couple thousand smaller files.
The results for writing files show a more significant difference. Writing to the Firewire drive is 35% faster for a larger file and about 54% faster for a couple thousand small files.