Guys, can you please help with one small issue

7x vega 56 rig 1450mhz core 1100 mem
srbminer 1.8.1
adrenalin 18.6.1
intensity 62,

miner is always startying HAVEN at 12600H/s. But if i stop it many times and restart, it will eventually start at 13000H/s. How can i get it to always start at maximum performance?

Thanks!