Zotac has just announced a new GTX 1070 graphics card. This one is quite a bit shorter than their 30cm AMP! GTX 1070. The GeForce GTX 1070 Mini graphics card (model: ZT-P10700G-10M) cuts the length down to only 21cm, perfect for your small form factor build.
The card makes use of a custom-designed PCB that is about 17cm in length. The cooling solution is actually a bit longer than the PCB itself. The dual-fan cooling solution is the same one that we saw on the GTX 1060 AMP! graphics card. It features two 80mm fans that sit on top of a dense aluminum fin stack that has two 8mm-thick copper heatpipes.
The card draws power from a single 8-pin PCI-Express power connector and it sticks to the NVIDIA reference speeds of 1518 MHz core, 1708 MHz GPU Boost, and 8.00 GHz (GDDR5-effective) memory. For display outputs you have three DisplayPort 1.4, and one each of HDMI 2.0b and dual-link DVI. The card is expected to retail for $389.