The GeForce GTX 1080 Ti is the top card to own if you have the coin, but the question is, do you stick with a reference card or splurge on an overclocked variant? Rather than answer that question for you, Zotac is covering all bases with four GTX 1080 Ti SKUs.
Sitting at the top is Zotac's GeForce GTX 1080 Ti Amp Extreme (ZT-P10810C-10P). The product page doesn't list clockspeeds for this card, though TechPowerUp has it on some kind of authority that it ships from factory clocked at 1,645MHz/1,759MHz (base/boost). Nvidia's reference clocks are 1,480MHz and 1,582MHz for the base and boost speeds, respectively.
Out of the four cards, this is the only one with a triple-fan cooling solution. It also has a 16+2 power phase design to help with overclocking and general stability. It draws power from two 8-pin PCIe power connectors.
Zotac's other overclocked GTX 1080 Ti is the GeForce GTX 1080 Ti Amp (ZT-P10810D-10P). Like the Extreme model, Zotac just lists "TBD" for the card's base and boost clocks. TechPowerUp says it has a base clock of 1,569MHz and boost clock of 1,683MHz.
This one also boasts a 16+2 power phase design, but with a different custom cooler—it has two fans instead of three. And like the Extreme model, it draws power from 8-pin PCIe connectors.
The other two cards in Zotac's GTX 1080 Ti lineup both stick with reference clocks, including the GeForce GTX 1080 Ti Blower (ZT-P10810B-10P) shown above. As it name suggests, it uses a blower-style cooler that ejects air out of the front of the card (and out of your PC case).
As the reference blueprint calls for, this one draws power from 8-pin and 6-pin PCIe connectors (one each).
The last card in the lineup is a Founders Edition SKU (ZT-P10810A-10P). Both it and the Blower card will retail for $699.
There is no word yet on how much the Amp and Amp Extreme cards will cost, nor when any of these will be available to purchase.