Speedtest shows fast connection but actual downloads are slow

Question

I'm struggling with my wifi setup at home. I've 2 floors apartment. Router is on the first floor (ASUS RT-AC68U) and my desktop PC is upstairs (w adapter ASUS USB-AC56).

I find the connection pretty ok, at least in theory (connected on 5GHz):

Speedtest gives me good results (given that I've 150mbps/15mbps connection from my ISP):

But whenever I'm trying to download something from Steam or just over http it's usually very slow and unreliable (more often like the second one in the picture):

Another one slow or the connection drops (hence aborted download):

Downloading file from a USB stick which is plugged to the router good results (127 / 8 ~= 16):

I almost can't download anything via the browser. Does anyone have a clue how to debug and analyze this behavior? Doing same things on a side-by-side Mac gives way better results.

Solution

I'd say the server you're downloading from is the one responsible for the lower download speeds. The 5.7 MB/s is by no means slow, but Microsoft has a lot of people hitting their server(s) and they are trying to load balance the traffic, so they can server all customers equally. It is very common that a lot of Internet servers, especially for larger sites, have download rate limiting enabled too.

The inSSID download may not be an extremely funded server like Microsoft has, so they only have so much bandwidth to give.

Another difference between speedtest, and the speed from a server you're downloading from is distance, latency, etc. Speedtests always pick a server that is closest to you in order to give you the best results. A speedtest simply measures the download between you and your ISP. It doesn't actually go out beyond your ISP. Once you go out beyond your ISP, many other factors come into play and can affect your download speed. Raw bandwidth is just one small part of the whole download process.

For example, if a user is fortunate enough to have a 1 Gbps connection, I doubt they will ever get a download that will give them 100 MB/s download speed because of the load balancing and other factors that come into play. However, having that 1 Gbps link to their ISP, could allow multiple users on the network to experience extremely high download speeds all at the same time. In your case, downloading at 5.7 MB/s (57 Mbps) is still extremely well. Even with that kind of download, you could download a 10 GB file in less than 30 minutes. If you got your full 125+ Mbps, you could download a 10 GB file in about 10 minutes or less.

Comments

[rafek]

That doesn't explain poor Steam download performance. It always hits the top possible speed.

[DrZoo]

@rafek that doesn't quite make sense? "Doesn't explain poor Steam download performance." "It always hits the top speed possible." If you're meaning Steam always hits the top speed, I've noticed the same thing. They probably don't have a download speed cap. I have a 100 Mbps connection, and Steam is the only one that ever hits 10 MB/s. When downloading stuff from Microsoft or other sites, I usually hit about 6.5 MB/s at the max.

[rafek]

Downloading same InSSIDer on a Mac hits way better speed. I've trided with couple of different downloads and they're around 30KB/s - 90KB/s on my windows box (the one I ve problems with) and quite normal speeds on the Mac. Clearly sth is wrong here.