Just gonna chime in on the driver.
I have one Strix RX480 8GB(Samsung) running with Uber 3.1 Timings @1180Mhz/2035MHz/0.963v on Win 10.
Before I switched the drivers I was getting 27.9Mh/s & after updating it's now at around 29.93Mh/s but there were some problems.
Before installing this driver make sure you're on 17.7.2 because older Crimson versions crash when trying to open Wattman (was using 17.6.2 and updated to the BETA driver) & ofc patching the driver if you're using modded BIOS.
For me voltage control/clocks are borked on WattTool (have to wait for AMD to release public SDK for the API to get it updated) and with MSI AB 4.4.0 @ BETA 16 I can only touch clocks but not voltages so I was only able to lower them using Wattman. Restarting Claymore also bumps up voltage again so I have to re-apply it through Wattman. Hope this helps someone.
http://imgur.com/WwCwBLXhttp://forums.guru3d.com/showpost.php?p=5459908&postcount=637 MSI AB 4.4.0 BETA 16 just released if anyone wants to try.
P.S. If the drivers are fake he'd ask us to install them in Test mode since I doubt faking MS & AMD driver sigs on Win 10 works?