One feature missing from the Gigabyte GA-H81M-DS2V is an internal 20-pin USB 3.0 connector. I believe this is inherent to the H81 chipset, as a maximum of two USB 3.0 ports is supported according to Wikipedia. I took a quick look at H81 motherboards on Newegg. Few have internal USB 3.0 connectors. ASRock H81M does, but right next to the connector you can see an Etron EJ168 USB 3.0 Host Controller.
My case (Cooler Master HAF XB EVO) has front USB 3.0 ports. It does not provide a USB 3.0 20-pin to USB 2.0 9-pin adapter, so right now I have been using a substitute that comes with a Lian Li case. Today I received the ORICO USB 3.0 PCIe expansion card with internal 20-pin connector. Installation is pretty straightforward.
I wonder if there is any performance discrepancy between different USB 3.0 controllers, so I decided to run a CrystalDiskMark on my SanDisk Extreme 64GB flash drive when it is attached to different USB 3.0 ports. The ones on the rear I/O are handled by the H81 chipset; the front ports are provided by the new ORICO card which uses a VLI (VIA) solution.
Performance is quite similar in this test. SanDisk Extreme is probably the bottleneck here. 200 MB is far from saturating USB 3.0. I will try to get my hands on a faster device and then do the test again. The Samsung’s 850 EVO seems a good candidate.