1. To connect multiple PSU’s to a motherboard (which is not meant for that), you will need an adapter similar to this https://www.ebay.com/itm/New-Multi-Power-Supply-Adapter-Connector-ADD2PSU-PSU-board-For-Miner-ETH-BTC/292195480750?epid=22006161000&hash=item44083534ae:g:RsgAAOSw7ChZeB01
- Connect power output from one PSU (the one connected to the motherboard) to the adaper and plug in the second PSU with its standard 24-pin output to the adapter.
- As soon as masterblock is switched on, the second power block will run by itself from the adapter.
- Important: Do not run an unloaded power supply (connect at least a fan to it)
2. It is important to remember that when you connect GPUs to two different PSUS, they should not be cross-connected. Which means, if GPUs are fed through the riser to one block, don’t feed them through the pci-e power cable to the other. That can lead to a poor performance of a motherboard.
3. If PSUs are purchased and the pci-e power cables are too short, you can use something like this https://www.ebay.com/itm/PCI-E-PCI-Express-6P-Male-to-6Pin-Male-Graphics-Power-Cable-Extended-Miner-Wire/282771015240?epid=908915615&hash=item41d6774648:g:S5kAAOSwkLhaMNOf
4. I wouldn’t recommend to use noname Chinese PSUs, which promise you 1500+W for 50$. In general, this product has poor quality and can damage your rig. It’s worse looking towards known/proven or local brands, which will be promptly repaired or replaced if a warranty case occurs.
5. From a technical point, PSU should be selected based on 3 general criteria:
- General power on a 12v bus: If you plan to use it 24/7, consider, that manufacturers do not recommend to load PSUs more than 80-85% of the announced power load
- I recommend looking towards efficient PSUs at least Bronze. At 24/7 and long term operation, you will gain in a lower energy consumption and lower PSU heat dissipation
- I suggest modular PSUs. They are often not much more expensive than conventional PSUs, but are much easier to operate and if you use the same power blocks in your farm, they can be replaced promptly.