Thanks for advice.
Locked the coolers at 60% and the core clock at 900 MHZ, that gave me the stable output of 115KH/sec on wpa cracking with heat sensor dancing around 80 degrees.
Unfortunatelly even constant cooler lock at 100% with core set to 1100 MHZ runs the card to 90 degrees in 90 seconds causing hashcat to stop.
Locked the coolers at 60% and the core clock at 900 MHZ, that gave me the stable output of 115KH/sec on wpa cracking with heat sensor dancing around 80 degrees.
Unfortunatelly even constant cooler lock at 100% with core set to 1100 MHZ runs the card to 90 degrees in 90 seconds causing hashcat to stop.