I have been mining for 2 months now and i started to run into stability issues.
1 of the things is that i can now only run 2x R9 390's because when i add another one or a 7750 the system will crash within hours.

I will get the red GPU is giving errors message.
When i pull the extra R9 and the 7750 it can run for a full week without issues. This dramaticly reduces hashing power and my ROI.

Okay, i have been using an OCZ 700W psu together with a 500W psu. Tried a 1400W psu instead of the 500W but got the same results.
Troubleshooting is a bitch at this point.


My question:

Is it mandatory for all cards to receive the bus power (through Sata conector) from the mainboard PSU or doesn't that matter ?