stock intensity of 20 is to high for the AMD 5850 , i set my at 16 and its @ 12% .. which is 4mhs not bad for a 5 year old card...
I was getting crashes and freezes from Dashminer on a 290X ever since the recent AMD Crimson driver updates. I set intensity down to 16 (inspired by your post) and so far things are running well again.
I'll tweak it for optimal running Real Soon Now, but meanwhile - problem solved. Thanks!
Edit: Update - Intensity 18 worked for several hours, but eventually gave the familiar AMD "driver failed and recovered" message. However, the system froze immediately after showing the message. While it was working, "Accepted" numbers were well down from I20 levels. It may be a while before I test again (I need a stable machine for other stuff) but so far, I16 is the only stable value I've found with the Crimson drivers on a 290X, although hashing is down of course from I20 levels. Before the Crimson drivers, Dashminer performed perfectly for me at the default I20.