I'm getting a lot of issues with the Claymore miner within NiceHash in the past week, anyone else getting this?
This happens on 3 separate rigs running different cards, Furys, 280 and 390.
What often happens is periods of rejected shares even though the cards are rock solid stable and periods of disconnects/timeouts, I've tried switching regions but the same issue. If I switch miners I get no issues, but of course Claymore is the best performing.
Nicehash seems to have been doing a lot more "switching" this past few days vs it's norm - which impacts Claymore's miner more due to the overhead of setting up the SSL connection.
R9 280x should run fine on Ubuntu 14.04 with the fglrx 15.12 drivers - but I think you have to manually download them and install, I don't remember them being an apt-get options anywhere offhand.
There is ZERO reason to run "newer" drivers on that card, as long as you don't have anything more recent in the same machine with it.