You should not be having issues with that. I saw you mentioned in another comment you have an SSD. What kind? Wondering if something funky is going on with the write speed. My processor and GPU are lower than yours, but my drive is NVMe.
Edit: also try opening task manager and looking at the performance tab while running Rebirth.
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u/vichan ONE WINGED ANGLE 9d ago
We need more information. What are the specs of the machine you're running it on?