Over the last few weeks, I’ve been speed testing USB 3.0 as an alternative to eSATA. I’ve got some results to report!
For spinning media, USB 3.0 is basically as fast as SATA. I tested several 2.5″ laptop drives from 5400RPM and 7200RPM for sustained writes, and the USB 3.0 caddy added no significant overhead. Here are the results:
Seagate 320GB 7200RPM: SATA – 291GB/hr, USB 3.0 – 288GB/hr
Hitachi 320GB 5400RPM: SATA – 272GB/hr, USB 3.0 – 272GB/hr
Hitachi 500GB 5400RPM: SATA – 303GB/hr, USB 3.0 – 302GB/hr
As most people will be backing up to spinning hard disks, I can conclude that USB 3.0 is as good as eSATA.
However, for SSDs, the story is different. USB 3.0 seems to bottleneck:
Kingston 128GB SSD: SATA – 793 GB/hr, USB 3.0 – 350GB/hr
G.Skill Falcon 128GB SSD: SATA – 479GB/hr, USB 3.0 – 200GB/hr
I find it weird how USB3.0 doesn’t just cap the transfer rate, but degraded the G.Skill’s transfer rate.
I also have a Patriot SSD that I haven’t yet tested, so I look forward to doing that and seeing if the results alter.
Conclusion: USB 3.0 is great for spinning media. Weird for SSDs. I need to investigate more.
Have a great weekend all!