This is not the most professional guide. In this videos I repair two old GTX 1070 ITX edition with a dead fans and turn them into blower style GPUs using a 6000rpm delta fan and a 2000rpm DC fan both 92mm in size. Then I compare the mining temperatures for mining Ether and Raven coin. The results are in the conclusion.
The GTX 1070 with its 8GB GDDR5 used to be the most versatile GPU in its time, my expectation with its performance is not related to its capability but with its temperature under load in crypto mining, as I had already replaced the thermal pads on the memory chips and the thermal paste on the GPU chip in the past, still the temperatures did not go down much as the cooling solution i.e. the heatsink contact surface is very small as these are ITX sized, single fan design based GPUs from Gigabyte. As one of the GPU had already developed a dead fan, and the other one also had a fan that was on the brink of failure, one could tell be the wobble in its spin and used to get jammed while spinning because of its worn axle, so I decided to go for the extreme in cooling for these GPUs, so I bought two high rpm fans, - one is a regular cabinet fan with non-variable speed of 2000rpm with a DC supply connector and the second one is the real delta fan used in servers for cooling it has a PWM connector with variable speed from 3000rpm to 6000rpm, once I mounted them on the shrouds, the test began with positive results, so watch the process and enjoy the experiment. Disclaimer – Please note that such high rpm fans are extremely dangerous, always use fan guards to prevent anything from getting in the fan blades while operational, do not try to play with such high-speed devices, this is an experiment and after the video was shot, I put on the fan blade covers for risk free operation and to avoid any hazardous situation.