There are a couple of things to take into account when asking whether or not the 1070 Ti can mine Ethereum. The first is the hashrate, or the number of calculations that the GPU can perform per second. The 1070 Ti falls somewhere in between the GTX 1070 and 1080 in terms of hashrate, so it is capable of mining Ethereum, but it may not be the most efficient option. The other thing to consider is power consumption.
The 1070 Ti uses more power than the 1070, so it will likely cost more to run. Overall, the 1070 Ti can mine Ethereum, but it may not be the best option for those looking to maximize profits.