WIFI Iperf stats - are these good enough for 4k?

Help and Support Vero 4K / Vero 4K +
1

The first day i had the vero i managed to stream 4k over wifi with no issues at all. I was was super impressed. Couple of days later i was having issues with streaming with buffering when there was none on the first day. I tried a powerline adaptor and also had issues with buffering. I decided to install iperf to diagnose the issue.

Please could some review these stats and let me know if they are good enough for 4k streaming.
I feel they should be, there are errors but not many. I also tried powerline adaptors which got very similar results except without any errors at all. I rebooted after changing network adaptors.

osmc@osmc:~$ iperf3 -i1 -t30 -c 192.168.0.2
Connecting to host 192.168.0.2, port 5201
[ 4] local 192.168.0.15 port 35822 connected to 192.168.0.2 port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 11.0 MBytes 92.4 Mbits/sec 7 99.8 KBytes
[ 4] 1.00-2.00 sec 11.2 MBytes 94.1 Mbits/sec 0 134 KBytes
[ 4] 2.00-3.00 sec 11.3 MBytes 95.0 Mbits/sec 4 127 KBytes
[ 4] 3.00-4.00 sec 11.3 MBytes 94.7 Mbits/sec 7 120 KBytes
[ 4] 4.00-5.00 sec 11.3 MBytes 94.8 Mbits/sec 6 113 KBytes
[ 4] 5.00-6.00 sec 11.3 MBytes 94.9 Mbits/sec 0 145 KBytes
[ 4] 6.00-7.00 sec 11.3 MBytes 94.9 Mbits/sec 5 135 KBytes
[ 4] 7.00-8.00 sec 11.3 MBytes 94.5 Mbits/sec 4 127 KBytes
[ 4] 8.00-9.00 sec 11.1 MBytes 93.6 Mbits/sec 5 118 KBytes
[ 4] 9.00-10.00 sec 11.3 MBytes 94.9 Mbits/sec 7 110 KBytes
[ 4] 10.00-11.00 sec 11.3 MBytes 94.8 Mbits/sec 5 101 KBytes
[ 4] 11.00-12.00 sec 11.3 MBytes 94.6 Mbits/sec 0 135 KBytes
[ 4] 12.00-13.00 sec 11.3 MBytes 94.8 Mbits/sec 5 128 KBytes
[ 4] 13.00-14.00 sec 11.3 MBytes 94.8 Mbits/sec 2 118 KBytes
[ 4] 14.00-15.00 sec 11.2 MBytes 94.2 Mbits/sec 2 110 KBytes
[ 4] 15.00-16.00 sec 11.3 MBytes 94.6 Mbits/sec 2 101 KBytes
[ 4] 16.00-17.00 sec 11.3 MBytes 94.7 Mbits/sec 0 135 KBytes
[ 4] 17.00-18.00 sec 11.3 MBytes 94.7 Mbits/sec 7 127 KBytes
[ 4] 18.00-19.00 sec 11.2 MBytes 94.1 Mbits/sec 2 120 KBytes
[ 4] 19.00-20.00 sec 11.2 MBytes 94.0 Mbits/sec 7 113 KBytes
[ 4] 20.00-21.00 sec 11.3 MBytes 94.5 Mbits/sec 8 103 KBytes
[ 4] 21.00-22.00 sec 11.3 MBytes 94.8 Mbits/sec 0 137 KBytes
[ 4] 22.00-23.00 sec 11.3 MBytes 94.6 Mbits/sec 3 128 KBytes
[ 4] 23.00-24.00 sec 11.2 MBytes 93.6 Mbits/sec 2 121 KBytes
[ 4] 24.00-25.00 sec 11.3 MBytes 94.9 Mbits/sec 5 111 KBytes
[ 4] 25.00-26.00 sec 11.2 MBytes 94.3 Mbits/sec 3 103 KBytes
[ 4] 26.00-27.00 sec 10.9 MBytes 91.7 Mbits/sec 1 107 KBytes
[ 4] 27.00-28.00 sec 11.3 MBytes 95.1 Mbits/sec 0 140 KBytes
[ 4] 28.00-29.00 sec 11.2 MBytes 94.0 Mbits/sec 7 133 KBytes
[ 4] 29.00-30.00 sec 11.1 MBytes 93.1 Mbits/sec 4 123 KBytes

[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-30.00 sec 337 MBytes 94.3 Mbits/sec 110 sender
[ 4] 0.00-30.00 sec 337 MBytes 94.3 Mbits/sec receiver

iperf Done.

The Mediainfo for Pacific Rim:
Format : Matroska
Format version : Version 4 / Version 2
File size : 78.4 GiB
Duration : 2 h 11 min
Overall bit rate mode : Variable
Overall bit rate : 85.5 Mb/s
Encoded date : UTC 2018-01-16 23:52:49
Writing application : mkvmerge v20.0.0 (‘I Am The Sun’) 64-bit
Writing library : libebml v1.3.5 + libmatroska v1.4.8

2

94 MBit throughput for a 85 MBit movie sounds too tight because of the overhead
It might depend on the network protocol you use but I guess this might not work stable

3

You are also getting a lot of retries. Just the first 4 seconds gave 18 retries.

1 Like
4

The speeds look OK but it does seem that they are not being sustained.

5

Thanks your comments made me diagnosed the issue further. I thought it very odd that the wifi and powerline were so similar in speeds.

Eventually after spending a few hours testing the whole network today i realised that a specific network port on the router was only running at 100mb rather than 1gb. My nas drive was plugged into this port.

I also tested every network cable i have to see if it can do 1gb, realised i had lots of old freebie cables bundled with various devices over the years that where cat5 that where also causing issues. So replaced them all.

This is my new iperf stats with wifi ac 80mhz running on ch 100.
I ran iperf for the powerline network, but they are only running at approx 93mb.

osmc@osmc:~$ iperf3 -i1 -t10 -c 192.168.0.2
Connecting to host 192.168.0.2, port 5201
[ 4] local 192.168.0.15 port 56595 connected to 192.168.0.2 port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 28.5 MBytes 239 Mbits/sec 0 516 KBytes
[ 4] 1.00-2.00 sec 31.9 MBytes 267 Mbits/sec 0 620 KBytes
[ 4] 2.00-3.00 sec 31.6 MBytes 265 Mbits/sec 0 662 KBytes
[ 4] 3.00-4.00 sec 30.7 MBytes 258 Mbits/sec 0 676 KBytes
[ 4] 4.00-5.00 sec 31.5 MBytes 265 Mbits/sec 0 694 KBytes
[ 4] 5.00-6.00 sec 31.2 MBytes 262 Mbits/sec 0 700 KBytes
[ 4] 6.00-7.00 sec 31.4 MBytes 263 Mbits/sec 0 719 KBytes
[ 4] 7.00-8.00 sec 31.5 MBytes 264 Mbits/sec 0 727 KBytes
[ 4] 8.00-9.00 sec 31.5 MBytes 265 Mbits/sec 0 736 KBytes
[ 4] 9.00-10.00 sec 31.7 MBytes 266 Mbits/sec 0 744 KBytes

[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 312 MBytes 261 Mbits/sec 0 sender
[ 4] 0.00-10.00 sec 311 MBytes 260 Mbits/sec receiver

iperf Done.

6

This looks good, should allow you stable 4k