it is true bensam. i tried on my old wonky miner and it shows the same drop. dunno if it's exactly the same issue, afaik AMD arch doesn't even have a TLB. now let's see how that 1070 holds up 
Just tested my r9 390 with Genoil on block number 10000000 (mem usage ~3.8G) - 17mhs ))) (~epoch 333)So Hawaii is also heavily effected but later ))
GTX1070 on block number 10000000 (mem usage ~3.8G) - 31mhs - not effected )) (~epoch 333)