I didn't think tile based renderer does culling - it just batches the tiles up and keeps them in cache instead of pushing the entire frame too and from memory - which decreases the needed bandwidth and obviously saves power. Like maybe the same hardware unit that does the tiling also does culling - but I don't think the two are completely related. Tom Peterson also mentioned that it uses GPU cycles, so it actually slightly lowers performance. They also turn it on/off in driver profiles, because it isn't worth doing in some titles. Also David Kanter's company has provided consulting services to AMD/Nvidia and other major tech companies. He's not like a random youtuber or something - he works in the industry.