[JohnR]

.. you have the right electronics!

Not impressed by an earlier effort measuring a USB3 drive, I tried again. This time with a Firmtek miniSwap/U3 holding an Intel 330 SSD. Computer is a 13" Retina MBP. Measured with Intech Speedtools Utilities:

4k random read/write: 21.2/29.6 MB/s.
10 M seq read/write: 418.5/429.3 MB/s

! I almost fell over.

By comparison, the same SSD in a cheap Vantec enclosure:

4k random read/write: 16.8/23.4 MB/s.
10 M seq read/write: 174.4/200.8 MB/s

That's a pretty big difference! Is it worth spending several times more for the speed? If you have paid for a fast SSD, it seems so...

For another comparison, here is the internal drive on the Retina MBP:

4k random read/write: 16.6/6.6 MB/s.
10 M seq read/write: 477.1/387.5 MB/s

I'm really surprised by the 4k random write number. The only place the internal drive is better than the external USB3 drive is for large reads 

As another surprise, I also tried the Firmtek enclosure w/ Intel SSD connected via an Orico hub. I was assuming that it would drop significantly. Not really:

4k random read/write: 20.7/29.6 MB/s.
10 M seq read/write: 417.3/416.3 MB/s

Wow, times are changing...

[jqp]

Yeah controllers(firmware), drivers, and busses really make the difference. I have a Samsung 840 Pro that I am finally putting into a desktop I have been building with the new Haswell cpu. There's no such thing as just an SSD and a computer. For this system, a huge SSD throughput difference in the different paths even on the same motherboard.

[skunark]

With USB3 and Thunderbolt you really have to read the specs of the drives to gauge performance as most single drives aren't much faster than the USB2.0 versions.    RAID0 drives and larger SSDs is where USB3 can capitalize on performance.  From the reviews of SSDs drives, for a given family, the smaller drives typically perform worse than the larger drives.

Is it worth spending the difference?  I would use SSDs for a laptop and boot drives in desktops and stick with HDDs (or hybrid) for the data with the exception of a fanless audio only system, I am considering using the $599 Cruical 960GB SSDs to eliminate the HDD noise.

[JohnR]

exception of a fanless audio only system, I am considering using the $599 Cruical 960GB SSDs to eliminate the HDD noise.

Hi, that's basically why I'm doing this. My desktop now is completely silent, except for one of the backup drives which only has to be turned on occasionally and which the next step is moving it to a network drive. In my case the 500G Samsung 840 completed the picture.

There is a plugpack down behind the desk somewhere that whistles a bit though... need to hunt it down

Went down the "almost silent" 2.5" (HDD) enclosure path. Yeah right.

Also went down the Thunderbolt-eSATA path. That was a bit pointless - more complicated and expensive, and not as fast! Strangely, Thunderbolt has turned out to be useful (to me) not for its speed, but it's adaptability - I use a display port cable to my external monitor for one port, and the other gets the Fireware adapter in it sometimes. At some point I'm sure the Ethernet adapter will be handy...

[JohnR]

I thought I might update this...

I did a bit more research and can't find anything else that delivers the same level of performance from a single-drive enclosure, whether USB3 or Thunderbolt.

Things may change but for the next few years, this path just seems to make a lot of sense to me. I ordered two more of the Firmtek drive enclosures.