Due to the fact that native USB 3.0 support is one of the main new additions to the Z77 Express chipset, and a couple of the motherboard had third-party, discrete USB 3.0 controllers on board as well, we did some testing to compare the performance of each solution.
For these tests, we connected an external USB 3.0 enclosure with a 7200 RPM hard drive installed within. Once the drive was connected, we fired up the ATTO Disk benchmark and ran the tests on the external drive.
As you can see, in terms of its write performance, the native Intel USB 3.0 performed right on par with the discrete ASMedia controller. Both Intel and ASMedia, however, had a clear advantage over the NEC controller when smaller block sizes were used. In regard to reads, the native Intel USB 3.0 interface trailed the ASMedia and NEC controllers at the smallest of transfer sizes, but Intel eventually surpassed the NEC controller and then just missed the mark set by ASMedia.
With that said, some USB solutions—like Intel and ASMedia—also support UASP, the USB Attached SCSI Protocol, which can boost performance significantly. We’re going to be experimenting with UASP in the near future and will have a follow-up with full performance data posted soon. In the meantime, if you pick up a Z77 board and don’t have the necessary software to enable UASP mode, these are the kind of numbers you can expect.