I try to set the overclocking at the command line (inside cgminer, while it is already running) but it cannot adjust the voltage. Stock voltage is 1250, so I enter 1.250, or 1250, and none of it works. cgminer doesn't even detect that the r9 290 has a voltage at all. Asus tweak only works on the first card. Other cardmaker overclocking software also doesn't work.