I have 3 MSI RX 570s 4GB cards, with modded BIOS using 1500 straps, all were mining happily at about .0885 vcore. All was fine for a long time. All 3 cards were drawing ~120 watts each.

But recently one of the cards started drawing a lot more power, it started jumping between 150 - 170 watts, card seems stable but as result runs too hot with fans at 100%. No changes were made at all.

Any advice on what the cause of this could be?

Thanks.