Using the /locatebiome command uses a very inefficient algorithm and can crash a server very quickly, even with max ram / CPU. This is very much unlike /locate, which is virtually lag free.

The easiest way to demonstrate this is the following:
1.) Place a repeating command block with a lever on top

2.) Write in the command block "locatebiome modified_jungle_edge" (any biome works, but modified_jungle_edge works best)

3.) Press the lever and the server will "crash" down to ~0.001 game speed

The algorithm could be vastly improved, like the one they use on chunkbase.com , which can locate biomes in the blink of an eye. Also, any operator of server can crash the server in seconds, and the server crashes almost instantly and command blocks must be turned off in server.properties .