So I played with win7 a bit more... Oh say 30 minutes, then decided to make the leap to Win8! Followed the instructions in the thread I linked earlier, however I didn't realize that 13.1 drivers do not work on the R9 290! After some slight panic shortly after installing everything and it not working at all (driver not compatible), I decided to try the new 13.12 drivers released yeseterday at techpowerup (
http://www.techpowerup.com/195941/amd-releases-the-catalyst-13-12-whql-graphics-drivers.html). Well low & behold uninstalled 13.1, reboot, install 13.12, reboot, and the 5 cards I have installed showed right up!
When I tried to run my original conf file though it was telling me I needed to lower thread concurrency... Then realized I forgot to do:
setx GPU_MAX_ALLOC_PERCENT 1
setx USE_SYNC_OBJECTS 1
After that it tried to start mining on all 5 cores... However 1 core's memory was only at 150MHz (but engine was allowed to 1040)?! Repeatedly tried to use the cgminer interface to change it to no avail. Then downloaded MSI Afterburner and tried to set all rates that way. Well after several crashes it was finally "sticking" and now it just works through cgminer. Not sure what the real "key" was, but it's working, somewhat...
So after getting that squared away, I had an issue that my old settings would crash the computer almost immediately. So now I'm trying to decrease intensity from 20 to 17, seems to be doing fairly well. Getting 4.25Mh/s from 5 R9 290's... That actually quit a bit lower than what I'm used to from each card. That equates to ~850Kh/s each, whereas in Win7 with 13.11 beta 9.5 drivers I was getting a solid 900Kh/s (3 of 'em 908 except one card was 900).
Next up, see if adding the 6th card plays nicely
Then see if I can "dial in" the settings for 13.12 like I did with 13.11 to get the most hashing per card