5850 low hashrate

[wacko]

Is your voltage regulation out of wack? Stock voltage on my 5850s is 1.088 VDC, and you can only change it in multiples of 0.0125. I would definitely try setting the voltage to 1.088 and see if that helps.

1.088 V is the default voltage for reference Radeon 5850. DirectCU isn't reference and it's common for original vendors' designs to use higher gpu voltage.