Test Setup, CrystalDiskMark
Test Setup: We tested the Asmedia 1042's UASP capability using Asus' P8Z77V motherboard, along with a Thermaltake USB 3 enclosure and a USB 3.0 Boost Cable solution. Our primary hard drive was a 1TB Western Digital Caviar Black (32MB cache).
The Asus USB 3.0 Boost Cable is meant to power a 2.5" drive or SSD; the Thermaltake unit can handle a standard 3.5" HDD. The initial test results Asus sent us leaned pretty heavily (though not solely) on ATTO performance. That's fine if you want a benchmark that uses highly compressible data algorithms, but we were interested in something a little more real-world.
We've included test results from CrystalDiskMark, PCMark 7, and a variety of real-world copy scenarios. For our storage devices, we picked three that seemed to bracket the sort of products end-users might be interested in. For an SSD, we used an Asus recommended Corsair Force 3 60GB, a VelociRaptor 1TB handled the high end of spinning disk performance, and a Caviar Green 1TB drive stood in for the millions of 5400 RPM external hard drives sold every year in the US.
In order to keep the graphs a bit more manageable, we used the HDD data for our real-world tests, but left them out of the synthetic CrystalDiskMark.
CrystalDiskmark: For CrystalDiskMark, we've decided to highlight just the SSD's performance. It's easier to parse the graph if you compare bar sets -- yellow to blue, and purple to green.
The Intel and Asmedia USB 3 controllers are well-matched in Normal mode -- and both leap ahead once UASP/Turbo modes are enabled. The Asmedia controller has a slim edge in the Sequential Read and 512K tests and a huge advantage in the 4KQ32 read test. The latter advantage is thanks to the parallelism we showed earlier -- commands can be processed independently from data flow and data streamed much more effectively as a result.