High CPU usage when using 5 replays 10 sec each

[Destroy666x]

I'm not too sure that's intended as I assume and see the replays are just stored in RAM. What's the CPU doing so extensively with higher number of longer replays? Shouldn't be encoding as that's done only once. Decoding also should happen once per video when they're played, when nothing is cached. Since it depends on video length, I assume it's not related to logic or text/progress bar sources.

Here are my entire settings:

(except time is at 6666 now which almost doesn't lag). My FPS is at 60 and I'm using NVENC 264. 32 GB RAM, i7 2.9 GHz, GTX 1080, Windows 10, latest OBS and plugin.