EOS 5d4 "busy", burst speed very low

[cputnam]

My new Eos 5d mk 4 has great burst speed in auto mode, but in any other mode it is extremely slow...like, 5 seconds per frame.  The dispay shows "busy" and the shots remaining indicator blinks.  Tried it in program and manual modes, with three different cards (one Lexar 12x 96 mb cf, 2 different Sandisk 32 mb SDHC-1 cards).  Why would the camera mode screw up the buffering?  Any suggestions? TIA

[PLee]

Turn off Digital Lens Optimizer.

[PLee · Accepted solution]

Turn off Digital Lens Optimizer. It's automatically disabled when the camera is in full Auto.