[How To] Check Network Performance with iperf3

Sometimes it is important to check the network performance between your OSMC Device and the device providing your media (NAS, Server, PC). Especially when you are connected via wireless the throughput variations can harm you viewing experience.
This short How To should give you the required information how to install iperf3 and how to run the respective tests. When doing these tests it is suggested to have a simple setup (single switch between Sender and Receiver and avoid other traffic on the LAN. Also if you want help please post full results including the used command line.

  1. Install it on the OSMC device with sudo apt-get install iperf3

  2. Install it on your other device in your LAN (NAS, Server, Router or PC) following the respective method from here iPerf - Download iPerf3 and original iPerf pre-compiled binaries

After we have installed it on both devices we can run the test:

  1. Start iperf3 in server mode on your central device (NAS, Server, Router or PC) with iperf3 -s

  2. Start iperf3 on the OSMC as client with iperf3 -R -c <IP of your iperf3-server>, this will run a test where the OSMC device will receive data from the Server

  3. Now to test the direction from OSMC to the Server we need to remove -R switch on the OSMC device iperf3 -c <IP of your iperf3-server>

While the -R test is the more relevant one (you normally use the direction where the OSMC device receives the data) it still also important to run the test without the -R option to ensure both receiving and transmission direction works fine.

This initial test should give you an idea if your connection works fine, depending on your connectivity you should see:
Wired 100 Mbit: upto 94 Mbits/sec
Wired 1000 Mbit (both sides): upto 940 Mbits/sec
Wireless (2.4 Ghz): ~20-50 Mbits/sec
Wireless (5 GHz): 60-140 Mbits/sec

Please, be aware that Gigabit Ethernet Chips on some devices like the Raspberry Pi3+ are internally limited due to their connection (e.g. USB2) and therefore bandwidths up to 940 Mbits/sec cannot be reached with these…

If you find any major discrepancies you should look at changing cable, ports or switches. If you connect by wireless than try to change the channel.
Retries are not of major concern (if numbers are reasonably low) as the only time you would get zero retries is if the receiver and every link in the chain is faster than the sender. Especially when wireless is involved retries are common.

For further testing you could either extend the testing with -t 60 (one minute)
iperf3 -t 60 -R -c <IP of your iperf3-server>
or try parallel stream -P 4 which can make sense on wireless
iperf3 -P 4 -R -c <IP of your iperf3-server>
or you can use udp packets instead of tcp -u (you need to define the stream speed with -b eg. -b 100M or -b 1000M)
iperf3 -u -b 100M -R -c <IP of your iperf3-server>

7 Likes
Problems with Gigabit Ethernet on Vero 4K +
4k uhd stutter or freezing up, audio dropouts
IPTV Isues
[4k+] [NFS] Extreme slow library update
Slow download speed on vero 4K
Play any movie will sometimes freeze my Vero
Seeing Vero 4K On Network
Random freeze / quit to menu on high bandwidth content
Start Video - just buffering
System really slow
New Vero 4k+ - Problems playing/scrubbing movies
Vero 4k+ + Kodi 19 + Plex = slow plex loading movies
Bandwidth needed to stream internally
Vero4k with usb ethernet adapter slower than on ethernet port
Heavy stuttering, pausing, loss of sound during video playback
Vero 4K+ v19 - Many Problems
Share files on 2 vero+'s
Raspberry Pi/KODI is freezing during movie play
Videos suddenly starts stuttering and shutting down
Video crashes when streaming from SMB share, but is ok via USB
3D Frame Packed output
Nfs mount don't work after kodi v19.1 migration
Slow wifi connection - buffer is losing the fight
Low download speed on new 4k+
(1) Change password SSH, samba, (2) win 10 samba access hangs
Adding Repos
Vero 4k with only front red led visible
Raspberry & Mycloud NAS failures
Vero 4k issues - speed and HDR
Rebooting 4k to bring up transfer speeds across network
Slow copying to Vero attached HDD
Slow internet speed - RPI 3B
1080 and 4K stutter on WiFi
Buffering over network, and then again .... not really
Super-noob, access Very 4K+ over network
Some questions about watching movies on my Pi 3+
Keeps freezing and requiring a power cycle since June Update
4k hevc stutter through smb
Navigation is very slow, and 4K playback frequently buffering
OTA TV stuttering
Vero 4k+ slow on WiFi, fine wired
SMB connection issue after June update
Movies crash/Stop after ~15 minutes
Frustrated playback issue and add to library issue
Delay on initiating playback
Losing WIFI Signal after a while
Freezing on high bandwidth 4k content
Buffering issues
HVEC Playback issues over LAN
Random No Sound or Stuttering Video - Vero 4K+
NFS and SMB, Neither work well!
NFS and SMB, Neither work well!
[TESTING] Linux 4.9 kernel and improved video stack for Vero 4K / 4K +
Can't get through a movie
Suddenly can't playback many files
Vero 4K+/OSMC not playing my 4K HDR
Bandwidth is really poor using wifi
Iperf3 install failed
My Vero 4K+ does not recognize my NAS' folders
(SOLVED) How to find root cause for buffering with 4K content?
Buffering Issues
4k files (Emby direct play) buffering on Vero 4k+
New bug in NFS? Almost nothing playing from my NFS share, started like four days ago
Corrupt Video after 30 seconds
Choppy and noisy audio playback after full reinstall and new raspberry pi NAS nfs share
Reboot required after watching 1 episode or switching channels
Transfer from Computer to Vero
New install on Raspberry Pi
Problems playing movies from NAS
[TESTING] Kodi v19 builds for Vero 4K / 4K +
PI4 with OSMC to read folder/files on Windows10 via NFS
PI4 with OSMC to read folder/files on Windows10 via NFS
New network woes
Google wifi router Synology shares extremely slow
Vero 4K+ Buffering issue
OSMC with Kodi 19.1 Playback of large video files stuck
Vero 4k+ big slowness after the Kodi update
Pi3 with 19.1 stuttering then freezing after few minutes of video playback
File manger not seeing sources
Error after November update
Increasing SMB server capacity
Relatively slow eth speed
Playback keeps stopping over network
Pi Zero 2 W Streaming Problem
Osmc stops streaming, cant access/control osmc anymore
Mapping NFS drive from OSMC
Vero 4k stutter with some dvb-t streams since nov. update
Vero 4k+ IPerf Results & Network Speed
RPi 3B+ Buffer / Stuttering Issues
Rpi4 with latest OSMC and 5Ghz only 70mbit
4K-Movie jerks and bumbs as hell from fileserver
[TESTING] Kodi v19 builds for Vero 4K / 4K +
New Additional Settings for Drobo NAS
SMB nearly unusable on Kodi 18.9
Troubles with huge file playback/cache?
Latest Stretch-Devel Update -- Extremely Slow Network/Streaming Performance?
Choppy playback since Leia
sudo apt-get remove iperf3 libiperf0

What did you try to indicate/solved with that?

1 Like

Ooh, I’m terribly sorry.
I was in the middle of creating that post and probably went on with other things and forgot about this.

What I was about to add was a way to delete the installed iperf program.
Just for peeps who tend to tidy things up after they’re done with it. :wink:

Perhaps add this last command in the How To?

It uses such little space that typing that command already takes more effort than the space it takes. Anyhow people now can find it in your comment

2 Likes

Thanks for this guide.
My Vero 4K is connected to WD Mycloud mirror NAS.
And I would like to know, maybe somebody of OSMC comunity using WD company NAS and know how to instal iperf3 on it.

Doesn’t support 3rd party apps so no chance to run iperf3 on it. Suggest to test iperf3 against other devices (like your PC).

Thanks