Create prores files that are not so heavy? (read)

I save the prores files on a normal 5400rpm hard disk. Since I have a rather poor pc, I convert mp4 files to prores to make them run more smoothly in Adobe Premiere. The problem is that the files are very heavy. I have no problem with the size of the files, since I have more than 2tb of space left. The problem is the rate of mb/s. It is 195mb/s and my hard drive is not that fast. I also have a ssd disk but it is where windows is installed and it has very little space.MY QUESTION IS IF SOMEONE WOULD GIVE ME A CONFIGURATION TO CREATE PRORES FILES THAT ARE NOT SO HEAVY OR BETTER, THAT DO NOT HAVE A HIGH MB/S RATE?I recently created a prores file of a short 4 minute youtube video in 1080p and 60fps. It weighed 300mb in mp4 and when creating it in prores LT it would weigh 5gb at a rate of 195mb/s.

I need it to be 100mb/s or less. The rest is all good.