500GB eSATA External Storage with Throughput Upto 67MB/s

I was suffering from full-hard-drive disease for a couple of months. So last week I finally ordered an external drive to hold the piles of data I store on my MacBook Pro. This is what I got:

• Hard drive: Seagate Barracuda 7200.10 SATA 3.0Gb/s 500-GB Hard Drive (16-MB cache buffer) - ST3500630AS
• Enclosure: Vantec NEXSTAR3 NST-360SU-BK
• eSATA Express Card 34: Vydeo eSATA 34: Dual Port 34mm Express Card

Everything came in mail today, so I unwrapped it and put it together.



The Seagate 7200.10 hard drive is a hard drive, there is not too much to say about it, except for the usual complaint that 500GB ain't 500GB of free space, you get 465.8GB with this baby.

The Vantec enclosure looks really good and has a very good feel to it. It feels much better than any other enclosure I put my hands on. Very sturdy, slim, well designed and well assembled. Thanks to the fact that it's aluminum based it keeps the hard drive REALLY cool - during heavy use it is just a bit warmer than my hand.

I picked the Vydeo/Meritline eSATA card based on the "feature set /price" ratio and didn't really know what to expect because there is not as much written about it on the Internet as I'd like. Luckily there were no surprises so far.

The card is based on SiI3132 chipset and the driver supplied with the card is an unmodified Silicon Image driver (version 1.1.5). When I tried to install it however, it didn't work. But the one I got from Silicon Image support site worked fine (version 1.1.9). I had to restart my MBP to get MacOS X to recognize it though.



An interesting thing that I noticed is that when I copy stuff from the external drive to my internal drive (not the other way around), my computer gets sluggish. Particularly, all the operations that needed to access the internal drive became almost unusable because of slow responsiveness. I'm not sure if it's the internal drive getting overloaded with all the traffic, or something else, but it happens only in this one scenario (using loading data from the external drive to memory causes no problems).

The only other complaint I have about the card is that it is relatively easy to accidentally unplug. It is safe enough to use on a desk, but I don't even want to think about the data corruption caused by an accidental unplugging while using the computer on my lap.

I ran a few very unscientific benchmarks to see what to expect from my new toys. Here are the results.

1. Copying my 13.22GB of mp3 files from the internal drive to the external drive:

   time cp -r ~/Music /Volumes/ExternalHDD/BackUp/

   8m29.645s = 26.5MB/s
   (Keep in mind that the internal drive is the bottleneck in this test, not the eSATA drive)
   
   I ran this test while in USB2.0 mode (the enclosure supports both eSATA and USB2.0) and the results were:
   16m8s = 14MB/s
   
   That makes the eSATA configuration 1.89x faster than the USB2.0 one.
   


2. Copying 13.22GB of mp3 files from one folder on the internal drive to another one:

   time cp -r /Volumes/ExternalHDD/BackUp/Music/ /Volumes/ExternalHDD/

   7m1.298s = 32.2MB/s
   Considering that the files had to be read and then written to the drive, the number can be doubled to get the combined throughput. This makes it 64.4MB/s
   


3. Creating a 10GB file using mkfile command and storing it on the external drive:

   time mkfile 10g /Volumes/ExternalHDD/10GB.file

   2m37.377s = 65.2MB/s
   


4. Creating a 5GB dmg image file using Disk Utility and storing it on the external drive:
   1m17s = 66.5MB/s
   


5. Encrypting a 5GB file stored on the external drive using openssl and storing the encrypted file on the external drive:

   time openssl enc -in /Volumes/ExternalHDD/5GB.file \
   -out /Volumes/ExternalHDD/5GB-encrypted.file -e -aes-128-cbc

   3m24.313s = 25.1MB/s
   Again, since I'm reading and storing the file on the same drive, the combined throughput is the double: 50.2MB/s.
   
   Since this is a test that is very close to the real world usage, I ran it with the disk connected via USB2.0. The results were:
   8m27.985s = 10.1MB/s or 20.2MB/s combined
   
   That makes the eSATA configuration 2.49x faster than the USB2.0 one.
   


6. Copying a 5GB file from the external drive to the internal drive:

   time cp /Volumes/ExternalHDD/5GB-encrypted.file .

   2m39.271s = 32.3MB/s
   


7. Copying a 5GB file from the external drive to the internal drive and at same time copying another 5GB file from the internal drive to the external drive:

   time cp 5GB-encrypted.file /Volumes/ExternalHDD/5GB-encrypted2.file&
   time cp /Volumes/ExternalHDD/5GB-encrypted.file .

   5m46.592s = 29.6MB/s (counting with 10GB of data being transferred )
   Again the internal drive is the bottleneck in this test.
   

Looking at these numbers I'm pretty happy with my purchase. Not a bad outcome for little less than $300 total.