Peering between your ISP and Valve is likely saturated.

Considering Valve has an incentive to make downloads fast (= more revenue), it's likely your ISP is being stingy in this case.

And ISPs in most of the western world have no incentives to fix it, instead trying to scam Valve and others to get paid twice.

The business model of consumer ISPs is "take the money and don't deliver" so this tracks.

I would have assumed valve use some third party CDN but yeah this would make sense I guess

It might have detected the wrong country/city for you. Check Settings -> Downloads -> Region

Otherwise it's just your WiFi being patchy. I think Steam is doing "friendly" bulk download, it slows down before the connection is saturated, to avoid disconnecting your wife/mum/siblings watching Youtube or on a videoconference.

> Wait, but you get 63MB/s down from steam?

I usually (but not always) saturate my downlink with Steam downloads... even back when I was a Comcast customer and paying for ~180MB/s (~1500mbit/s) asymmetric service.

I believe that I have noticed that smaller games (~a few hundred MB or maybe a GB or two) will download quite a bit slower than large games, but I'm not very confident in that observation.

Comcast has Steam server(s) colocated within their network in my immediate area. I’ve observed that less popular downloads tend to connect to external servers in the next state over.

> I believe that I have noticed that smaller games (~a few hundred MB or maybe a GB or two) will download quite a bit slower than large games, but I'm not very confident in that observation.

You can see that on the HellDivers screenshot, it takes 20 seconds to reach 500 Mbps, because TCP takes a while to adjust the bandwidth and is very conservative. TCP and home computers are not designed to make use of gigabit connections.

> ...it takes 20 seconds to reach 500 Mbps, because TCP takes a while to adjust the bandwidth and is very conservative. TCP and home computers are not designed to make use of gigabit connections.

I very much doubt that that is an artifact of TCP. I can go from nothing to 10gbit/s symmetric in 100->200ms when running Iperf3 over TCP against another one of my LAN hosts.

And, back when I had a 1.5gbit/s Internet downlink, it took far, far less than 20 seconds to reach > 500mbps for big Steam downloads and other such well-provisioned things.

For me it varies a lot. Sometimes I get 800 Mbit and sometimes like 80 Mbit. Mostly closer to 800, tho.