Emulator

Game Name?
Tested: Rayman 3 and Rayman Arena, may effect other games

Game ID? (right click the game in the game list, properties, info tab)
GRHE41 for Rayman 3, GRYE41 for Rayman Arena

MD5 Hash? (right click the game in the game list, properties, info tab, MD5 Hash: Compute)
40386ae7cb46600bf05e8980c0773ffc for Rayman 3
4e7b4dd0444ebfeb7ec2ab253116d437 for Rayman Arena

What's the problem? Describe what went wrong.
Any builds after and including 4.0-8919 no longer emulate disc load times accurately, at least on the two games I have tested. In both cases after build 4.0-8919 the load times decreased by around 2 seconds, equivalent to if "Speed up Disc Transfer Rate" were checked. I have verified using recordings from a Wii (albeit not my own, but from someone I trust) that the previous, longer load times were accurate.

What steps will reproduce the problem?
Time a loading screen on either Rayman 3 or Rayman Arena (other games may be affected, I do not currently have the resources to test that) on both 4.0-8919 and 4.0-8916. On build 4.0-8916, the load times should be around 2 seconds longer.

Which versions of Dolphin did you test on? Does using an older version of Dolphin solve your issue? If yes, which versions of Dolphin used to work?

4.0-8919 - FAILURE
<=4.0-8916 - SUCCESS

What are your PC specifications?
Intel 4690, Nvidia GTX 970, Windows 10 x64, Samsung 850 Evo (on which the game is stored)