Quadro 4000

[Frontiers]

Basically both Quadro and Team Red pro cards designed for working in different thermal loads when cards working in pro applications: it's not continuous 95-100% chip load during hours of gaming, it's somewhat different mode say roughly 50% of time chip have high utilization and other roughly 50% of time have low or no at all utilization. And cooling systems tuned with such loads in mind for not being very loud and cooling down when card in low chip utilization phase. And looking to some pro cards with IR-vision device when card constantly loaded to 90-10% for hours - some pro models may be hotter than good gaming 3 top-flow fans designs with same but differently configured chip and different drivers.
So Folding with expensive workstation cards which at constant full chip utilization, when looking to space around their chips - may run hotter at constant full utitilization than 3 fans gaming cards of good designs - may be not the best idea if looking for long term hardware reliability.

On my 'cheap' Linux Mint 20.1 box a 1050Ti gave around 300,000 ppd

There is Covid19 Project 13477 with very low atom count. When it meets with Linux Mint 20.1 and 750Ti clocked to 1400 MHz with 2 fans tuned to have <70 C at GM107 chip - it gives very good for GM107 395000 PPD from only 45-50 watts per card. After some initial batch of two times slower projects - they may meet for weeks of only 13447 coming with short breaks for 1-2 days to slower projects. So if you have some 750ti's - you can try them for 13447.

[bruce]

It would be a waste of money to buy new Quadro cards for FAH. You're paying extra for capabilities that are not critical for FAH. (memory parity, faster FP64 calculations, etc.)

On the used marked, it's hard to tell. I'd look for the price of an comparable GeForce card and allow a small price penalty for the equivalent Quadro.