So a fortnight ago I purchased a Z87X-UD5H and an i7 4770K, all was alright (mostly) until I tried to use an Icy Box USB 3 enclosure (IB-RD3640SU3).
Using all the default BIOS settings (except Init Display First - I'm using onboard graphics) the enclosure connects/disconnects continuously from the moment it is plugged in. This happens on all the USB slots. The enclosure is not at fault, it worked perfectly on my old P67 mobo. Setting XHCI mode to disabled, and ditching the Intel eXtensible host controller, the enclosure works fine, although only at USB 2 speeds. I've also tried the F7 and F8a bios'es, with no luck.
I have purchased a Renesas D0720201 based PCIe USB 3.0 card, and when connected to this, the enclosure works correctly, at full speed, therefore confirming my suspicion that the motherboard is to blame. I have used the drivers off Gigabyte website, as well as the latest ones off station-drivers.
Do I have a duff mobo, or is there something I'm missing?
My System:
Gigabyte Z87X-UD5H
i7 4770K 3.50GHz
16GB Kingston HyperX Genesis 1600MHz
OCZ Revodrive 3 X2 240GB
6x SATA III WD drives
Antec P280
Windows 8 Pro 64bit