ETC mining on Pascal cards seems to be broken. Got only a half hashrate (17-20 MH/s) on 1070ti when mining ETC (ETH is ok).
Tested on Nicehash and Ethermine ETC pools.
I would not say broken, but ETC is in a later dag epoch which may hurt your card more then it should (but its normal etc is slower then eth due to this). I assume at least the general implementation for etc and eth has same quality.
No it's a more general issue past EPOCH 319... If this issue is still present on ETH when it reached this level it will throw all PASCAL card out for ETH if not fixed.
The difference is not large enough to explain such a speed difference