Could someone please enlighten me about how to put the Pascals in P3 state?
Or how to set the memory clock of the P2 state?
I've recently noticed that the NVidia Inspector (1.9.7.8) doesn't work with Pascal cards.

Can you explain what these P states are and how to change them on other gen cards? I would assume it's for maximum power and not to downclock.

Could someone please enlighten me about how to put the Pascals in P3 state?
Or how to set the memory clock of the P2 state?
I've recently noticed that the NVidia Inspector (1.9.7.8) doesn't work with Pascal cards.

Compute mode is P2 while during gaming P0. OC P0 core state. P3/P5 low power not used during compute.

You can't set P2 memory state like some Maxwell's.
To OC P2 memory - set memory clock on P0 higher.

Voltage control doesn't work on NVidia Inspector (1.9.7.8) (you don't need this on Pascal to OC). Pascal doesn't care for more voltage.
Best overclocking values are found at stock.

Core offset based on the out the box boost so if the card boosts to 1900MHz set P0 core to +100 to get 2000MHz. If the card stay's below 60C then <>12.5Mhz increment throttling is kept minimal.

Thank you for your advice. It's working.

I've mistook the short and the long names of the power states.
Performance level 3 - P0
Performance level 2 - P2
Performance level 1 - P5
Performance level 0 - P8

Compute mode is a mixture of P0 and P2 (i.e. memory clock comes from P2 but GPU clock comes from P0)