The F90 uses an 8-speed ZF automatic (not DCT) with the M5 CS receiving the updated ZF8HP76 unit; the choice over DCT was made for traction and daily-driver forgiveness.
Transmission Type and ZF8HP76 Update
BMW F90 M5 · drivetrain
The F90 uses an 8-speed ZF automatic (not DCT) with the M5 CS receiving the updated ZF8HP76 unit; the choice over DCT was made for traction and daily-driver forgiveness.