Windows + the AMD Stream 2.4 + newer Phoenix max out 1 CPU core per video card. This problem doesn't happen on Linux. Whats interesting though about the sempron 140, is idle it uses 30-35W, full load its 45W, so not that much of a difference in power usage.
Thank god...!!
I just purchased some AMD 160u single core 20W cpus... so they should be able to run multiple video cards without any problems on linux? Just not on windows?