Our small battery of tests shows again that completely passive cooling configurations in the 60 to 75W category are only possible after a handful of compromises. Choose one of two options: either install a set of low-RPM fans to create a little airflow inside your case, or allow the GPU to hit its temperature limit in a passively-cooled enclosure and live with the reduced performance. Leaning on a fail-safe isn't really ideal though, so we don't love that idea.
Realistically, the upper limit for completely fanless operation remains around 40W, where almost all of the card's power is dissipated as waste heat. In that situation, the best option is to manually set a power target of 50%. Otherwise you're going to see protection mechanisms kick in and force the power limit anyway.
Given the circumstances presented, we must recommend at least some air circulation in your case for a project like this one. With that in mind, when we think back to our original passively-cooled GeForce GTX 650, not much has changed in the past three years. After all, we aren't picking cards that use dramatically less power. What they do, however, is deliver significantly better frame rates, improving the performance to power ratio versus three years ago. The frustration of coming up short on a completely passive solution is dampened somewhat by the GeForce GTX 1050 Ti's excellent response to a humble, low-RPM fan.
MORE: Best Deals
MORE: Hot Bargains @PurchDeals
It seems that Sapphire copied the idea ;)
I would much rather see a passive water cooled setup with no fans, only the pump.