My ethereum GPU miner had been down for 6 months after accidentally bricking an AsRock board while trying to update a bios. I've since purchased a used ASUS b250 mining expert. I spent last weekend installing my old R9 380 cards (because I had them) and fired the thing up to find that I'm getting >49mh/s per card with stock settings. Overclocking today, I'm getting >53mh/s per card.
I figured these would be worthless, but I'm pleasantly surprised. Can anyone explain why card that seem to be reported as getting mh's in the 19 range are getting 50+?
This is a bug actually and most likely its as a result of a badly modded memory strap or just the miner software you are using is having an error reporting the correct speed. I had that GPU back in 2016 and it hashed at 20MH/s or so and was pretty quick back in the day.
Are you getting any hardware errors? If so flash back to stock bios and see what speed you get.
If you have no HW errors then mine for a day and see what average speed you get with your pool, most likely it will be no more than 20MH/s.