Okay so I figured I'd let everyone here know, sgminer 4.0.0 (cgminer 3.7.2 fork) has added support for a comma-seperated gpu-threads value. This should make it possible to run diff model cards all from the same instance of sgminer. This script is obsolete (sorry OP). Sgminer is scrypt only BTW. Also included in this great fork is many fixes to make the R9 290s stable! Fantastic stuff.