Some things to consider:
- You shouldn’t change settings so extremely. If you’re running stock, you just need to lower core or memory settings in small increments. Underclocking can cause just as many issues. That’s why I refer to a sweet spot.
- A good practice to follow as well is to put both GPU and the riser it’s connected to on ONE PSU. Don’t separate them.
- I’ve noticed that EWBF generally places the cards in the order in which their plugged in on the board (but your mileage may vary). That being said, take a look at this post that might help in identifying individual cards.
There’s a few key things missing from your posts so far though that might help paint a better picture. What are you temperatures like? What are the stock settings of your cards? All of my cards have entirely different settings to reach the same Sol/s and some cards can take much higher overclocks while others I’ve had to underclock slightly. Some of those cards are same model and manufacturer.