might be of help, my cards are all 290x version and they are each different brands(asus,xfx, ect ect)
When i first started the rig with each card i could never go over 8192 for TC after 2 days of wtf i finally striped the rig down and formated my ssd and reinstalled fresh windows 8. updated all drivers and made sure my bios was gtg then ONLY installed what i needed: amd drivers, amd sdk, cgminer 3.5, cgwatcher ect ect. i also installed google chrome but thats because internet explorer sucks. after that i was able to increase my TC to 32768 with intensity 20 and got 950k/hs each card with no issues, i ended up turning down intensity to 19 an only lost 75k/hs overall which isnt bad to not fully maximize my cards, makes me feel better if nothing else but anyways. if you can i would backup what you need format you HD or get a fresh HD and do an install of OS of your choice then see if that changes anything. i know it seems like alot but worth a shot if you have 3 hours to kill to do everything. word of advice i learned was before i did all that i downloaded all drivers for the mobo, amd ect ect put them on a pin drive that way once i was finished with windows i just put the pin drive in and when down my list and installed reboot repeat till they were all done. hopefully this helps you out some.
I will try this as soon as I can and I will let you know, I hope it helps also if I set intensity from 13 to 14 it starts getting a lot of HW.
thanks