Re: 1600 series Nvidia GPUs are significantly better than everything else.

Show me the numbers for how AMD polaris has the best price performance.

I bought a Sapphire RX570 4G gaming for 130 brand new in january. It's got Samsung memory, can hold 2100MHz mem speed and gets 31-31.5MH/s mining ETASH
Mining CN Heavy: 915H/s
CN turtle: 8500H/s
CN Waltz: 1300-1320H/s

Any GTX1660Ti is twice more expensive where I live.

I'm not trying other algorithms, because I mostly want to mine privacy based coins.

New Nvidia Geforce GTX1660Ti is cool for mining Ethereum. The price of it is also OK, it varies between 299 and 349 USD. And its memory is 6-8 Gb. The tests of this stuff have shown 30 MH/s and less energy consumption.

I can buy 2 RX580 8GB for the same price, and the 580 hashes Etash at 31MH/s. Unless you pay more than 0.16USD/KW/H, you have a faster break even with a pair of 580s.

1660Ti: https://www.coinwarz.com/calculators/ethereum-mining-calculator/?h=30.00&p=80.00&pc=0.16&pf=0.90&d=1877509334277410&r=2.00000000&er=0.02981921&btcer=5379.70000000&hc=300.00
2X RX580 8GB: https://www.coinwarz.com/calculators/ethereum-mining-calculator/?h=62.00&p=200.00&pc=0.16&pf=0.90&d=1877509334277410&r=2.00000000&er=0.02981921&btcer=5379.70000000&hc=300.00

Also for 700USD, the Radeon VII can pull 100MH/s (undervolt + OC memory).

I agree that mining ETH with 1660 or 1660ti doesn't make sense right now; better to mine another coin and exchange it to ETH with them.

As ETH is scheduled to switch algos soon, I would avoid choosing GPUs based on their ability to mine Ethash.