It's a server on a shared 1Gbps port, but the output depends on the I2P network demand and how congested the port is with neighbors.

Right now I'm averaging about 13Mb/s constantly, which in the last 12 hours or so the minimum demand was 8Mb/s and the max being 20Mb/s.

But if I wget a speedtest file...

$ wget -O /dev/null http://mirror.leaseweb.com/speedtest/1000mb.bin 
--2020-12-20 10:40:43-- http://mirror.leaseweb.com/speedtest/1000mb.bin
Resolving mirror.leaseweb.com (mirror.leaseweb.com)... 209.58.135.187
Connecting to mirror.leaseweb.com (mirror.leaseweb.com)|209.58.135.187|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1000000000 (954M) [application/octet-stream]
Saving to: '/dev/null'

/dev/null 100%[============================================================================>] 953.67M 46.8MB/s in 22s 

2020-12-20 10:41:06 (42.4 MB/s) - '/dev/null' saved [1000000000/1000000000]

Then I'm getting about 47Mb/s down while the router is still running/serving traffic.

Old server was 'faster' but I had monthly data caps and I never took advantage of the faster network anyway, I2P was never demanding enough to need to serve that much traffic at once:

wget -O /dev/null http://mirror.leaseweb.com/speedtest/1000mb.bin
--2020-12-20 10:44:16-- http://mirror.leaseweb.com/speedtest/1000mb.bin
Resolving mirror.leaseweb.com (mirror.leaseweb.com)... 209.58.135.187
Connecting to mirror.leaseweb.com (mirror.leaseweb.com)|209.58.135.187|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1000000000 (954M) [application/octet-stream]
Saving to: ‘/dev/null’

/dev/null 100%[============================================================================>] 953.67M 60.1MB/s in 12s 

2020-12-20 10:44:28 (82.1 MB/s) - ‘/dev/null’ saved [1000000000/1000000000]