Where's multi threading support? CPU bottleneck

My PC specs are
ryzen 7 1700 overclocked to 3.7ghz
32gb 2933mhz ram
amd r9 390 8gb
1tb intel 660p m.2 ssd
Apparently my cpu’s 16th thread is getting choked with 90-100% cpu usage while all my other threads are sitting idle. While my game can 90% my gpu when there’s not much going on. When I’m near a lot of effects such as rivers, fires or Thrall’s earthquake spell, the game frames go from 110-115fps all the way down to 20-25fps making it unplayable. My cpu thread 16 maxes to 100% and gpu drops all the way down to about 35%. There’s clearly a problem with the game only using only 1 thread. This is 2020. No game should be using a single thread running the entire warcraft engine.

bump, different specs but same problem. game should not be grinding to a halt

blizzard does not support overclocking. you can use task manager to specify how many cores/threads the game runs on. look for the warcraft 3 process under details then right click and select affinity. the settings have to made every time you run the game however.