Emulator

Game Name?

Sonic Adventure DX - GXSE80
Sonic Adventure 2: Battle - GSNE8P

What's the problem? Describe what went wrong in few words.

Tiny Chao Garden runs at less than 1% VBA-M side if you manage to get it connected.

What steps will reproduce the problem?
[Don't assume we have ever played the game and know any level names. Be as
specific as possible.]

1. Load Sonic Adventure 1 or 2 and head to the Chao Garden.
2. There should be a GBA thing there. Basically, connect the GBA to Controller port 2 or whatever you want. Load the Bios. Make sure your VBA-M is configured for connecting to dolphin and stuff. It's dead simple, there's a guide on the Wiki.
3. Assuming it connects (it won't always) the Tiny Chao Garden will run at maybe one or two frames a minute. There isn't much else to say.

Dolphin 3.5 and 3.5-367 are old versions of Dolphin that have
known issues and bugs, so don't report issues about them and test the
latest Dolphin version first.
Which versions of Dolphin did you test on?

4.0.2 and 4.0-1242

Does using an older version of Dolphin solve your issue? If yes, which
versions of Dolphin used to work?

Nope.

What are your PC specifications? (including, but not limited to: Operating
System, CPU and GPU)

Core i5 3570K @ 3.4GHz, Geforce GTX 760, Windows 7 x64

Are you using the 32 or the 64 bit version of Dolphin?

64bit

Nothing else I could do except maybe make a video.