I'm going to keep this short and sweet, the past couple of weeks I've been experimenting with custom roms from the various different people who have made them. Mostly testing on a couple of 290's I've had.
I will post pictures/detailed findings another day but for now I'll just explain what has happend.
MOST of the roms ended up decreasing my hashrate significantly, while not making a huge difference to power consumption. Most roms dropped my 290 down to around 20-24. These roms included heloix, stilts, and insanities roms. insanity's rom did the best maintaining a consistent 24. BUT here is the problem, overclocking I can achieve 27 pretty easily, and with a rom I've been making recently for myself (Purely for fun) I've gotten it so the memory timings are tight and core is around 1.06. with this I keep a steady 29 mh/s and a temp around 68-70c.
I'd like to know about your experiences and hashrates with custom roms, I haven't seen much about it lately.