Same Bios on two MSI 480 Gaming x 8GB, but different power draw

Hello guys

i have flashed the exact same bios on my two MSI 480 Gaming X 8GB, which both have Samsung VRAMs. With WattTools, I checked whether both Cards run on same Core and MemVoltage, they do. But the first card draws ~10 Watts more Power (looked up in MSI Afterburner) then the second. Clocks, Hashspeeds are the same, FB Usage are the same

What am I missing?

The only difference I can find are the differen Vins in WattTools: GPU1 (higher power draw) shows 12.2250V, GPU2 shows 12.156V, how can I change these?