The theoretical speed of a bus like USB is different from what devices are able to achieve in practice. USB 2.0’s theoretical max is 480Mbps, while USB 3.0 jumps that up to 4.8Gbps.
Today we’re benchmarking the Plugable USB 3.0 HDD Docking Station, which is capable of running on either USB 2.0 and USB 3.0 systems, to show what to expect in terms of performance.
While the low-level Windows drivers are different for USB 2.0 (Microsoft EHCI) and USB 3.0 (NEC/Renesas XHCI), above that layer, everything is common, using the drivers already present in Windows. This includes the existing Microsoft USB Mass Storage class driver that does much of the heavy lifting for USB-attached disks.
About the test platform:
- Windows 7 Professional 64-bit
- Intel Core i3 CPU 530 @ 2.93 GHz
- 6GB RAM
- Plugable PCI Express to SuperSpeed USB 3.0 2-Port Expansion Card (NEC/Renesas Chipset)
- Provided USB 3.0 cable from the Plugable USB 3.0 HDD Docking Station.
- Western Digital Hard Drive WD1002FAEX 7200RPM SATA (1 TB)
- HD Tune 2.55 / 512KB Block Size
- CrystalDiskMark 3.0.1 64-bit / 9 Test Runs / All Tests
- ATTO Disk Benchmark / Direct I/O / Overlapped I/O / Transfer Size: 0.5 to 8192 KB / Total Length: 256MB / Queue Depth: 4
HDTune reports an Average Transfer Rate increase from 36.4MB/sec to 97.9MB/sec. This is about 168% faster than USB 2.0
CrystalDiskMark reports a sequential Read increase from 38.43MB/s to 107.6MB/s and a Write increase from 36.61MB/s to 88.75MB/s. That’s a 179.9% increase for Reading and a 149.2% increase for Writing.
ATTO Disk Benchmark reports a Read increase from 38402 to 105268 (KBytes/sec) and a Write increase from 35696 to 85762 (KBytes/sec) . Those are 174.12% increases for Reading and 140.25% increases for Writing accordingly.
If we were to get the average of the 3 tests we would get an average speed increase of 162.2%. A transfer that would take about 5 minutes on USB 2.0, would complete in roughly 2 minutes on USB 3.0.
These numbers may increase slightly in the future with USB-attached SCSI support, USB 3.0 streams, and other driver/firmware updates. But 2-3 times faster in practice is a good baseline for expectations.
We welcome any comments, corrections, or your own benchmark results.[amtap amazon:asin=B003UI62AG]