I have recently bought nvidia HX170 with a server box type (motherboard) and made all the required installation and configuration on HiveOS.
Once the GPU connects to the mining pool, in 3 minutes it gets overheated (above 90c) and turns off. However, the server box fans are on and the weather temperature is around 20c.
Had a similar problem with one of my GPUs. i concluded that the fans where old and not moving enough air. i ended up swapping the whole heatsink and fans with another GPU that i had that was dead. it still gets up to 79 degrees Celsius but its not overheating and shutting its self off now.
On that note, it appears different GPUs from different manufactures use the same bolt pattern for their GPU’s. so if you can find someone tossing a old GPU, see if you can salvage the heatsink.