What version Claymore's runs the best with AMD rx 570 and 580 8gb cards and what driver should I install?
On Windows, I'd go with either the blockchain driver or something around 17.11 (whatever the first WQHL version is after they added "large page" support to the mainline drivers).
On LINUX, 17.50 seems a lot more stable than the blockchain drivers, but you have to modify one of the driver modules to get ANY support for undervolting or underclocking the core.
The latest Adrenalin driver works perfectly well for RX cards. It's pointless to intentionally install older drivers.
Does it work with BIOS modded cards?
I've seen conflicting info about which Adrenalin drivers do so and which don't.
That's also why Claymore's recommendation of 16.12.x made ZERO sense, as 16.11.x and up DISABLED support for BIOS modded cards while 16.9.x and 16.10.x DID work with them.
You will get much better performance, in my experience, from the latest Adrenaline drivers.
Here is the trick for modded bios files: If these are fresh cards, apply the bios mods using ATIFlash, install the new driver but do not restart.
After installing the Adrenaline drivers on a rig whose cards have modded RX bios mods, run 1.4.6 of atikmdag-patcher.exe prior to restarting. Then restart. All should be good.