What is the current settings set for the OCR activity in scanning? Is it set to accuracy? If this is the case it will take significant processing power dependent on the type of image and the size of it. If you are currently on RIO or Avante this should come with the licensing of the distributed computing cluster. This allows for OCR to be scheduled overnight or live depending on if you have dedicated machines and other factors. You should contact your VAR or Account rep to see if you have that license available.

If not you can scan without that process and do a search for documents that need to be OCR'ed when you are not scanning or not actively using the machine and OCR those documents. As I mentioned before this uses a good amount of resources on your machine so the machine will be bogged down during that time.