nvenc session limits on cards

Does anyone have a list of session limits on each quadro card? I found a good list of nvenc supported cards here http://wiki.avblocks.com/wiki/about-avblocks/about-hardware-acceleration/ but doesnt having anything on sessions limit. Trying to get a couple low cost quadro cards to handle multiple ffmpeg nvenc encodes not worried about speed but quantity I’d like to be able to handle at least 4 encodes at once. I have room for 4 cards in my server so I was looking at the quadro 410 since they are cheap on ebay. Will the 410 handle 1080p encodes with on 512mb of vram? Right now using a gtx 660ti but its limited to 2