Performance - HD Tune File Benchmark
HD Tune's File Benchmark profiles performance using a single file size, but different block sizes. So I ran it on all drives to provide a different view of performance. Here are the plots for your perusal. I'll summarize the data in the next section. Note that it takes a block size of at least 64 KB to get best performance.
Figure 12: Buffalo DriveStation USB 3.0 - HD Tune File Benchmark
Figure 13: Seagate BlackArmor PS 110 USB 3.0 - HD Tune File Benchmark
Figure 14: WD MyBook 3.0 - HD Tune File Benchmark
Performance - Vista SP1 File Copy
If looked like there was no worry that my NAS Testbed system with its RAID 0 array would limit test results if I used it to run a file copy test between it and each USB 3.0 drive. So that's what I did, using my Vista SP1 filecopy test, which copies a test folder containing a single non-compressed ripped DVD. The 4.35 GB (4,680,843,264 bytes) folder contains 38 files of various sizes ranging from 1 GB to 10 KB.
Figure 15 pulls together the file copy test results, HD Tune Benchmark and HD Tune File Benchmark test results for easy comparison. I also included a test of the Buffalo drive connected via my testbed system's normal USB 2.0 ports for comparison.
As usual, there is no exact correlation between the File Copy and HD Tune tests. But relative ranking are the same in each test method. Buffalo's drive seems to have a write performance advantage over both the WD and Seagate products. While the WD and Seagate drives seem more alike than different, which is surprising given their different geometries (2.5" vs. 3.5"). Depending on which benchmark you prefer, the Buffalo drive comes in between 84 and 93 MB/s.
Figure 15: Write performance comparison
Read comparison is surprisingly different, with this time the 3.5" drive WD and Buffalo products more matched in speed than the WD and Seagate. The WD MyBook 3.0 bested the Buffalo in two out of three benchmarks, although significantly only in the Vista SP1 file copy test (117 vs. 111 MB/s).
Figure 2: Read performance comparison
Bottom line is that USB 3.0 provides 3 - 3.5X write and 3 - 3.3 X read speed improvement over USB 2.0.
Drive To Drive
Since I had the luxury of having three USB 3.0 drives on the bench at the same time, I figured I might as well see how they did doing a drive-to-drive copy. Table 2 summarizes the results.
|Buffalo - WD||67.97||64.25|
|Buffalo - Seagate||66.98
Table 1: Component summary
It looks like something is holding back performance, because all the results are lower than I got from the Vista SP1 file copy tests to and from the internal RAID 0 array in the test bench system. Since USB 3.0 is supposed to support bi-directional transfers via dedicated SuperSpeed transmit and receive channels, I wouldn't think that the problem is there. So my suspicion is that the USB 3.0 host interface drivers may not quite be tuned for drive to drive copying at this point.
As is true with all data transfer technologies, the big numbers that are featured prominently in advertising are nowhere near what you get in practice. And so it is with USB 3.0. That 5 Gbps (600 MB/s) maximum spec is limited to 500 MB/s in the first PCIe X1 host adapters. And the limitations of single-spindle SATA drives knock it down further to the high 80 MB/s for write and 100-teens for read.
Although this is more than a 7X drop from the maximum numbers waved around, the first crop of USB 3.0 drives can still deliver better than 3X the speed of USB 2.0 drives, essentially marrying internal SATA drive speeds to the convenience of external drives.
Updated 3/22/2010: Clarified PCIe slot compatibility
Table 3 shows that although the cost premium percentage is significant, the dollar amount isn't too bad to swallow. But don't forget to add in the cost of a USB 3.0 adapter (~$30 and up) and remember that you'll only be able to upgrade desktops with a spare PCIe
X1 slot or note / lap / net books sporting an ExpressCard gozinta.
|Manufacturer||USB 3.0||USB 2.0||Difference|
|Buffalo||Buffalo DriveStation USB 3.0
|Buffalo Drivestation Turbo USB 2.0
|$137 (eCost)||$100 (eCost)|
|WD||MyBook World 3.0
|My Book Essential
|$160 (Amazon)||$109 (Amazon)|
Table 3: 1 TB USB 2.0 / USB 3.0 Drive cost comparison
Still, USB 3.0 drives are a relatively inexpensive way to significantly reduce the time you spend waiting to move your big ol' media files around. Just allow a little more time for USB 3.0 to USB 3.0 copying!