on zen protocol in stand alone mode (ie no gpu acceleration, purely the 215+ itself), around 380 mhs for a 215+ @ ~185 clocks. at ~15 watts. 2 core miner (0.11d). someone mentioned thats about what a rx580 does, dunno myself. ive clocked mine up to 191 with no issues. there is no real "stock" clock on acorns as it depends on the bitstream, but 170 (or maybe it was 150?) or so is more or less the recommended starting point for this particular bitstream.
keep in mind this is alpha, unofficial software, and not officially by squirrel.. this is from gpuhoarder done as a quick and dirty proof of concept kind of thing. real numbers will have to wait for the official squirrel miner.