Dear Apple developers, after downloading Big Sur to my iMac (Retina 5k, 2017, 4,2 ghz quad_core, intel I7) the performance became terribly slow. I am working as professional photographer and photo editor and this upgrade is a disaster in regard to the speed of starting up and performance in general. Under Catalina my processing workflow was fully satisfying, in speed and switching between the several software packages which I am simultaneously running (Adobe Photoshop, Lightroom, ON1, NIK, etc). Please fix it!