This should be interesting to watch.
https://www.phoronix.com/scan.php?page=news_i … ersave-GameMode

"Jason Ekstrand of Intel's open-source Linux graphics driver team ... shared that using the "powersave" governor with Intel graphics on a Gen11/Icelake setup (in this case, a Razer Blade Stealth 13), led to 25~30% better performance for the recent Linux game port Shadow of the Tomb Raider compared to the "performance" governor as set by default with GameMode..

It makes sense though since with integrated graphics the power envelope is shared between the CPU cores and graphics. In the performance mode of quickly ramping up the CPU cores it may deprive the graphics, depending upon how CPU vs. GPU bottlenecked the software is. "