I am referencing the attached video.  
I noticed this timing difference while syncing to test the visual changes made to the video output when using codes on a N64 Gameshark Pro 3.3. The right side of the screen has footage with codes utilized. The left side of the screen has footage without codes utilized. Supposedly, these settings are designed to manage dithering, blur, and antialiasing. I do see a difference in the sharpness between the right and left sides of the screen (with and without codes, respectively).  
  
I know there are timing and resolution differences between PAL and NTSC versions of the console. Here I am using an old US (NTSC) console and inputting what are supposed to be codes for the NTSC version of Super Mario 64.  
  
It seems they affect game speed as well, which, to me, was unexpected. I wonder if anyone has any idea why or how this occurs. It would seem the Gameshark substantially affects gameplay timing, which in turn affects speed runs and controller input timing, among other things, even when not intended for such purposes.  
  
I can't have been the first to notice this. Does any wise wizard more well-versed in the wild ways of Gameshark wodding ... modding ... have any answers for me? I am open to broad or fine-tuned questions/discussion about all aspects of the issue at hand.

Much Love to ALL!

N64 Gameshark Pro 3.3 - Timing / Game Speed difference when cheat codes activated?