Any adapter complicates the system and reduces its reliability.
Chinese adapters have a lot of marriage. A consequence may be the burnout of the video card or MB connectors.
I have long been in a mining, I communicate with people who have 100-1000 video cards. Everyone prefers to take a ready-made verified solution.
Solve yourself.
By "ready-made verified solution", you meant to go with Mining specific Motherboard right?
There are a huge number of motherboards that are sold on the market for years and have long been used in mining. For example, H81 Pro BTC, H81 Pro BTC R2.0.
Personally, I think that there should not be more than 6 video cards in the farm (I do not think this is the only right opinion, but my 3 years of experience has shown that this is correct).
Miners usually disperse video cards, and not all work perfectly in this mode. The farm will constantly hang up, the wachdog will constantly reboot the system. After a while we will get broken computer parts. It is very difficult to find a bad video card when there are 8 or more video cards on the farm( there can be several of them )
I'm using the GA-970A-DS3P. Everything works in stock mode, you do not need to make any adjustments in the BIOS. 5 video cards are detected without problems.
The processor for it costs 5-6 dollars (AMD x2 240-x2 250). This MB is sold in stores in my city and it is given a 3-year warranty. Also it is very in demand in the secondary market. For incomplete 3 years, not one has not broken out of 20 Motherboard and colleagues have been working for 4 years.
This is what I call a ready-made verified solution.
But most people do not want peace of mind, so they constantly invent a bicycle.