Low hashrate only on GPU0

[MiroslavCrypto]

Hi gents,
as you can see, everything is identical, however hashrate on GPU0 (first - long PCIe slot) is significantly lower. HDMI cable and monitor is connected to internal CPU Intel GFX, so there is no reason for behavior like this.

Please help, tnx!

[Rusipa]

Power supply?
Which one?
Connections to psu?

[MiroslavCrypto]

2 kW.
PSU is out of question.