I was working on encrypting a few files on my computer and I was using OAEP for padding with RSA. I noticed that it was taking a long time to encrypt some of my files with a small block size, so I tried to encrypt the same files with a much larger block size and it finished encrypting incredibly fast. I was thinking that the number of encryption cycles since there were so many blocks and/or the amount of padding used could be the reasons why it was so much lower when I tried to encrypt the files with small block sizes. Does the number of encryption cycles and/or amount of padding used from smaller block sizes compared to large block sizes impact the time. If so, why is this? If there are other reasons too as to why RSA with OAEP encrypts files much faster with larger block sizes compared to smaller block sizes, I would love to learn more about that!
Disclaimer: I completely understand that RSA is NOT meant for file encryption, I am just trying stuff.
Thank you in advance for any logic behind this that you can provide.