passive mining in file server. (a few questions)

[miyav]

we have build file server from scrap components. The server will serve 20 client.
I said we should do a miner. because we found video cards and more core cpus from scrap
we looking for a server chasis and power supply with sufficient capacity.

server OS : Linux
Moederbord: Asus KGPE-D16 (refurbished from gittigidiyor 110$)
Processors: 2× 16-core AMD Opteron 6272, 2,1 GHz (from scrap)
RAM: 8 x 4GB DDR3 + 8 x 4GB GB DDR3 (from scrap)
STORAGE: 6 x 500GB SATA (from scrap)
OS STORAGE : 64 GB SSD (from scrap)
GPU : 2 x AMD Radeon R9 280X (from scrap, we think we have repaired)

what should the strength of a suitable power supply unit as capacity?
after completing the deficiencies, which coin should we mining?

[melpheos]

RX280 currently has negative rentability.
No point with such low end card except if you don't care about your company electricity cost

[miyav]

RX280 currently has negative rentability.
No point with such low end card except if you don't care about your company electricity cost

the server will obviously be open. so we did not care about the extra electricity cost.
maybe the cards are still defective. we will continue to try