This page for the SB6183 at the top lists the download speed as 686Mbps but if you scroll down to the specs it lists the download speed as 400Mbps, so which is it? https://shop.surfboard.com/sb6183-surfboard-cable-modem/. Also this other page lists 400Mbps as well https://www.surfboard.com/products/cable-modems/sb6183/ but during speed tests, I can get over 500Mbps so that makes me think it is 686Mbps but all the pages make this pretty confusing.
Also, what is the max upload speed? Since there are fewer upstream channels in the modem than downstream channels, the max upload speed is usually less than the download speed. Based on this article, I’m guessing 200Mbps but does anyone know for sure? https://kb.netgear.com/000060401/What-is-the-difference-between-DOCSIS-3-0-and-3-1