Hi,
You should not have any issues with 80k images, even if they are all in one catalog. If you experience low performance, try to regenerate the previews (you can delete the content of the "cache" folder)
For large number of images, I would recommend using a catalog with referenced imaged, not managed, as it gives you the flexibility of where you store your images:
Example of a possible scenario:
- C1 catalog + previews + adjustments on a fast SSD
- Recent images or images still under processing = SSD or fast disk in a RAID 0 configuration, where performance is number one
- Move finalized images to a long term archive location such as a RAID1 array, where performance is second to data safety.
In relation to the specific C1 catalog file itself: It is a relational database wich contains a reference to the images (regardless of how you use C1), similar to LR but with a simpler structure. Managing hundred of thousands of records should not cause any trouble with most modern computers.