Ok, so it looks like everyone else is getting approximately the same hashrate difference for R9 390 vs. RX 480. I get 260 H/s and 190 H/s respectively with mine (both 8 GB). So my question is, is it expected that the 480 hashrate is only 73% of the 390? Is it because of the lower power consumption on the 480? With every other miner/currency so far, my 480s hash at about the same rate as my 390s. Is this something new with v8.0?
No it is not. It is because 290/ 390(x) are high end cards vs 470 low-mid/ 480 mid level, amd has not released that high performance gpu yet.
470/ 480 owners were lucky to enjoy hig end hashing rates at one algo with some bios modding. Today ancient 290 hashes more than 470/ 480 with the same or better hash/ watt ratio, better get used to it.
ps. what where those every other currencies where 480 matched 390?