Claymore, any idea what the following might be?

4x RX470, win10:

10:56:51:597   1150   em hbt: 0, dm hbt: 0, fm hbt: 63,
10:56:51:597   1150   watchdog - thread 0, hb time 78
10:56:51:613   1150   watchdog - thread 1, hb time 219
10:56:51:613   1150   watchdog - thread 2, hb time 219
10:56:51:613   1150   watchdog - thread 3, hb time 94
10:56:51:613   1150   watchdog - thread 4, hb time 109
10:56:51:613   1150   watchdog - thread 5, hb time 234
10:56:51:613   1150   watchdog - thread 6, hb time 23828
10:56:51:628   1150   watchdog - thread 7, hb time 23688
10:56:51:628   1150   WATCHDOG: GPU error, you need to restart miner

Faulty GPU, or Riser?
Thanks in advance, if you have a XMR address I'll buy you an untraceable beer^^