Maxtor MaxLine Pro 500GB drives in 2-way stripe

My storage needs have hit 500GB, which means that one of my backup systems was due for an upgrade in capacity. I purchased two Maxtor MaxLine Pro7H500F0 500GB bare drives at zipzoomfly.com ($239.99 each), and installed them into a FirmTek SeriTek/2EN2 (an exceptionally well-built 2-drive external SATA enclosure).

Next, I created a striped RAID volume with the two new drives, using Mac OS X Disk Utility.

2-way striped RAID volume

It is always wise to run the DiskTester test-reliability command (“disktester test-reliability BackupDuo”) overnight on new volumes that are to be put into production—which I did. No errors were detected.

The new volume was then tested for performance on the Macbook Pro using the FirmTek SeriTek/2SM2-E ExpressCard 34 adapter, which provides two external SATA II ports. I also performed the identical test on the PowerMac G5 Quad (using the Sonnet Tempo E4P PCI Express card).

The results are quite good, though they are about 25% slower for writes than the 300GB Maxtor 7v300F0 (see Feb 16 blog entry). But they are in a different enclosure, and tested with an updated system, so this is not a surety.

Observe how performance drops on the outer tracks of the drives; speed is only about 60% of maximum as data is read from the outer tracks. This is true whether you use a single drive or a striped RAID. But at least with a striped RAID (in which the hard drives work in parallel to store alternating chunks of data), worst-case performance still remains well above that of the maximum performance of a single drive. When backing up 500GB of data, a 4-way stripe can accomplish the task in about 90 minutes; on a single drive that jumps to about 6 hours—long enough to discourage regular backups.

---------- Averages for "BackupDuo" (2GB/32MB, 3 iterations) ---------
Area (928.8GB)    Write MB/sec    Read MB/sec
       0%             122.3          132.4
      10%             127.3          131.9
      20%             128.3          131.0
      30%             126.4          126.8
      40%             125.2          124.1
      50%             122.0          120.9
      60%             114.4          113.4
      70%             109.2          107.2
      80%             100.1           98.5
      90%              89.2           87.8
     100%              75.2           74.6
Average write speed across the volume: 113MB/sec
Average read speed across the volume: 114MB/sec

Command "run-area-test" executed in 1238.39 seconds.
				

--------------- Averages for "BackupDuo" (2GB/32MB, 3 iterations) --------------
Area (928.8GB)    Write MB/sec    Read MB/sec
       0%             122.3          133.9
      10%             126.5          133.7
      20%             128.7          131.1
      30%             126.7          126.6
      40%             125.6          124.5
      50%             121.9          121.7
      60%             114.0          114.0
      70%             108.9          108.0
      80%              99.7           99.0
      90%              89.0           88.3
     100%              75.2           74.9
Average write speed across the volume: 113MB/sec
Average read speed across the volume: 114MB/sec

Command "run-area-test" executed in 1236.13 seconds.