I would rank in this order of highest performance tax FROM MY EXPERIENCE
PMDG 737 (I’m using this mod though PMDG 737 700 4K & HD Wear and Tear Textures | JOIN DISCORD FOR ALL UPDATES AND VARIANTS | for Microsoft Flight Simulator | MSFS )
FENIX A320
BAe 146
Maddog MD80( I’m using this mod though RELEASED! MD-80 Hi-res VC project)