Rightly or wrongly, the Overwatch tick rate, that being the frequency at which the game on your PC receives updates from the server, has been a point of contention for a lot of players. The game's normal rate is 21Hz—that's 21 updates per second—which some people believe is just too slow for a competitive shooter. In June, Blizzard added a high bandwidth option to custom games that enabled play at 60Hz instead, and it apparently went over well, because it's now being rolled out to all games in both Quick Play and Competitive modes.
The high bandwidth option in Overwatch increases the tick rate from 21Hz to 63Hz, Community Manager Lilyrra explained on Battle.net. “Since we know that not all internet connections are equal, we’ve also added in tech that will automatically and adaptively scale down your update rate if we find your connection can't keep up. Similarly, because high bandwidth servers (as the name suggests) will increase your bandwidth consumption, we’re also looking to add an option to self-limit your update rate in a future patch.”
This isn't necessarily going to change your life, or even just your Overwatch experience. Game Director Jeff Kaplan told Eurogamer in June that in most cases, complaints about the tick rate are actually rooted in latency problems: What we used to refer to colloquially as “lag” back in the days when we were shooting at each other over phone lines.
“I think players have latched onto server tick rate as being the reason that certain things happen. One of the things that players are upset about is that if they get shot, where they perceive they were behind a wall, that this is a problem with server tick rate,” he said. “Certainly there are contributions that could happen with both the server and the client update rates that could cause something like that to happen, but usually, in most cases, you're talking about latency.”
Nonetheless, Lilyrra said the increased rate “will help the game feel more responsive.” High bandwidth support is being rolled out now, but Lilyrra warned that it could take a few weeks for the process to be completed in all regions.