[HELP] why the capacity is too big?

[kwan0220]

I set the settings below, set them to 120fps settings, and turned the encoding, and the work progress shown during the encoding was well below 800MB, but the results continued to increase to 3GB to 4GB.

There seems to be something wrong, but I'm not sure what the problem is.

Just in case, I'll take a screenshot of the settings I touched and upload them.

I'd really appreciate your help.
I'm a huge beginner in video encoding, so I'm sorry to ask you questions often.

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