I have three r9 280x cards. I use ubuntu server 14.04 and installed the amd catalyst driver using this guide as reference:
http://spacience.blogspot.com.tr/2015/11/gpu-mining-in-ethereum-1404-from-scratch.htmlI installed atitweak to set the clock speeds and needed to install a minimal X11 to set the clocks and to see the temperatures.
I put a script in cron run at boot to start xinit in a screen and set the clocks and start the miner in a screen too. it works very stable.
My rig has only 5GB RAM and 5GB swap space.
Thanks for the tips - used to mine on Ubuntu 14.04 (back when DarkCoin/DASH was still competitive with a GPU) with the Catalyst drivers and semi-automated with cron jobs and BASH scripts. If Win7 proves unstable I'll gladly spend an afternoon switching back to Linux. Aside from the girlfriend's gaming computer, the miner is actually the only Windows machine in the house (typing this on my laptop running Ubuntu MATE

)
What clock speeds did you end up settling in on with your 280x's? Did you just adjust core clock speed or did you play around with memory clocks as well? I've got -mclock at 1500 and -cclock at 1150 and things seem stable, wondering if you can push these cards to 1200 without too many rejects.
Wow, thank you so much for those links! Tremendously helpful. Unfortunately though every dropbox link I've clicked in the Google Docs spreadsheet is dead :/