How fast are the 3TB disks when loading a database from a text file? How much overhead does raid impose? This test will invoke many different types of IO and takes about 20-25 minutes. The workload varies and alternates between disk intensive and CPU intensive.
The drives tested are:
* Segate ST3000DM001-1CH1
* Western Digital WD30EFRX-68A 0A80 (also touted as WD Red NAS)
* Toshiba DT01ACA3 ABB0
Out of interest, I also had some 2TB Seagate ST2000DM001-1CH1 for testing. It turns out that the 2TB Seagate is faster than the 3TB model.
The objective of the tests was to find out which of these three drives was fastest for various tasks, then purchase several of those drives for use within a single server. Ultimately, this will be a server running FreeBSD 9.1 with 8-10 HDD ZFS running as raidz2.
Ideally, I could purchase 8 of each type of HDD and test them under ZFS. On my personal budget, that's not feasible. Instead, I am buying one disk of each type and testing them individually. This is under the assumption that if one clearly outperforms the other, a group of those same disks would also outperform the others.
I plan to do more tests, but for now, there is a clear winner for a single ZFS HDD. The Toshiba DT01ACA3. The time to load up the database nearly 8% faster than the WD30EFRX, and 24% faster than the ST3000DM001. But only 13% faster than the Segate 2TB model.
It is interesting to note that the Seagate was faster than the WD on UFS. But the Toshiba won on both ZFS and UFS.
I also did a test of 4x2TB Segate ST2000DM001-1CH1 in a raidz2. That turns out to be 16% faster than a single HDD. All of these tests are done without any ZFS tuning whatsoever.
I compared raidz2 with non-raidz. Conclusion: raidz2 imposes a 2.3% performance hit.
I compared raidz1 with non-raidz. Conclusion: raidz1 imposes a 1% performance hit.
Now my decision is: do I want the faster Toshiba drive with a one year warranty? Or the slightly slower Western Digital drive, with a three year warranty?
For the record, the average time for this test, taken over
I have an ugly spreadsheet with the results at the link below.