In the latest 3ds Max nightlies (https://nightlies.chaos.com/#/phoenix...) I sped up the Source emitting from many particles. This scene is a test for how many particles can be used in a Source.
Here is a liquid simulator in ocean mode with a wave force. It creates foam and splash, and in a second fire/smoke simulator the foam emits smoke, while the splash emits fuel and temperature and burns.
The liquid simulator has 6 million voxels, while the Fire/Smoke simulator has 30 million voxels. The foam particles used in the smoke source vary in time, but go up to 300'000, while the splash particles that emit from the fuel/temperature source go up to 100'000.
The liquid simulation took 20 minutes, the fire/smoke simulation took 3 hours on an AMD Ryzen Threadripper 3970X 32-Core Processor 3.70 GHz with 64 gigs of RAM. The water uses V-Ray SSS, and the 720p render took 42 hours for 630 frames.