Thunderbolt faster than USB 3 - even with single drives

[theSeb]

Nice article from tomshardware

http://www.tomshardware.co.uk/my-book-thunderbolt-duo-pegasus-r4-2big,review-32484.html

Interesting bits:

It's particularly notable that even a Thunderbolt link with multiple peripherals daisy chained onto it has sufficient bandwidth to enable full performance from downstream devices. Meanwhile, USB 3.0 slows down for every component added to a hub.

A quick breakdown of the single-drive observations:

• With a 3.5” hard drive, Thunderbolt proves faster than USB 3.0 by a small margin.
• With a 3.5” hard drive, the benefit of Thunderbolt compared to USB 3.0 increases as you add devices to the same interface.
• With a slower 2.5” hard drive, Thunderbolt performs about on par with USB 3.0. A daisy chainable device is needed to demonstrate an advantage.
• Regardless of the hard drive, Thunderbolt performs faster than FireWire 800 and USB 2.0 by huge margins.
• Do not assume an SSD in an external enclosure is going to be faster than hard drives.

Thunderbolt's benefits become clearer using single-drive devices with 3.5" disks. Moving a single file to the GoFlex Desk resulted in similar performance from Thunderbolt and USB 3.0. However, USB doesn't support command queuing. As a result, Thunderbolt takes a 22% lead when transferring bulk files. This is also an advantage when it comes to editing video, as data caching behaves similarly.

This critically important advantage doesn't get enough attention. With USB, the interface bottlenecks performance, not the devices themselves. As an example, if you burn a DVD on a USB 2.0-based writer and write to a thumb drive, those conflicting operations could yield a useless coaster. Although USB 3.0 facilitates a lot more headroom, the technology is similar, and bottlenecks remain probable.

Thunderbolt alleviates interface limitations. Yeah, one LaCie 2big can "only" hit 350 MB/s in sequential reads. But a second 2big in the same chain can hit 350 MB/s, too. You can use those two drives, plus something like BlackMagic’s Intensity Extreme (a Thunderbolt-based external capture device used by professionals to edit 1080p content) and not have any of those three devices stepping on each others' toes. If that matters to your application, then spending money on high-end hardware probably isn't your top concern.