More on my cheap GPU experience.
I got a Tesla K40m. This card is meant to be used in workstations and datacenters. It doesn't have a fan. Instead, it has a massive heat sink. It's assumed that there is enough airflow to keep the thing cool.
I'm using the card in an external enclosure. In theory, I could have gotten required airflow but I decided to go alternative way.
Initially I used a fan that is attached on the side of the card.
It did keep the card cool, but was very loud. The noise was too loud to do any work.
It could have been a good option for a data center, but not for an office desk.
My next idea was to try liquid cooling. I got a GPU mounting bracket from NZXT and Corsair fan from e-bay.
The end result looks great and is quiet enough.
My noise baseline is the fridge. My laptop and the GPU enclosure are quieter than the fridge.
@benis it works. Temps are reach 70°C. I would go with a bigger radiator - 140mm or even one that hosts 2 or 3 fans. My current radiator is for a 120mm fan.
I had a broken Titan card and decided to use a fan from there.
I replaced the heat sink, glued the fan. The result worked, but still was loud.
To mitigate the issue, i got a fan controller. It slowed down the fan when the card was cool.