RX570 Underperforming

[cover2sink]

https://i.imgur.com/SMEmJpd.jpg

TB85 mobo 8gb ram

GPU 0, 3, 5 = RX570 armor 4gb GPU 1,2 = Vega 56 GPU 6 = RX580 XFX

The 570's have the same memory, bios mods, and roughly the same OC. Is the variation pretty standard even though everything is the same? Any advice?

[MATHReX]

Each and every GPU is different even if they are of a same brand or model.
There is something known as silicon lottery, it's just that your GPU #5 may have lower ASIC quality than others and thus a bit lower hash rate.
So, It's normal.