Questions
Q1
How to let system work with over 3 VGA cards via BIOS setting for Bitcoin Mining ?

1. BIOS Settings :

Model : TB250-BTC
OS : Win10 64bit
VGA Card : Radeon RX470 Graphic Card *6ea


 Chipset > Miner Mode > Set to [Enabled]

2. OS :

(1)Before install special graphic driver:

(2)To install special VGA Driver (without WHQL).
After install this VGA Driver, system can recognize all 6 of Radeon RX470 VGA Cards.

Note:
(1)
If you do not follow above both of BIOS Settings and installed VGA Driver,
then the Windows OS will show below result (3 of RX470 cards will show yellow exclamation mark.)

(2)
More H/W Settings,
please refer to Biostar Bitcoin Mining Hardware Guide webpage.
https://www.biostar.com.tw/app/en/event/bitcoin/index.htm