I know you don't need to connect a monitor to it! I've emphasised this enough I think with the 3 or 4 posts I made.
Hot, been looking for a spare GPU for my HTC for awhile now. Heat OP
You don't need to connect a monitor for its intended purpose (running computing tasks). The reason I asked whether it could make sense is that in the link provided by one user it appeared to only be 2x the power for computing tadls compared to a GTX 1080 that costs over 5x less (you could use it for computing without plugging in a monitor, like crypto miners do). The answer from another user (thanks @plork) seems to make sense: in certain calculations (double precision, whatever that means :D) it's apparently 10x as fast as a GTX 1080 for less than 10x the price... so there's the value proposition :)
Can I commute to work on this instead of a bike?