RPi 3B+ gigabit ethernet bad download speeds.

[RPIgoodSBC]

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[tfontaine]

I found the following settings help transfer speeds for the Ethernet port
Run as root

Code: Select all

sysctl -w net.core.rmem_max=8388608
sysctl -w net.core.wmem_max=8388608
sysctl -w net.core.rmem_default=65536
sysctl -w net.core.wmem_default=65536
sysctl -w net.ipv4.tcp_rmem='4096 87380 8388608'
sysctl -w net.ipv4.tcp_wmem='4096 65536 8388608'
sysctl -w net.ipv4.tcp_mem='8388608 8388608 8388608'
sysctl -w net.ipv4.route.flush=1

If I change this value, it looks like it worked, but checking afterwards, does not seem to have changed it.

Code: Select all

[email protected]:/$ sudo sysctl -w net.core.wmem_default=65536
net.core.wmem_default = 65536
[email protected]:/$ sudo sysctl -a | grep core.rmem
net.core.rmem_default = 163840

I was very enthusiastic and hoping this would fix it, but forgot to check what the default values were...
The speedtest did not change anything for me.

I also have 200 Mbit down / 20 up, but never get these figures from the download.
Only if I connect the Pi to my Ziggo (provider) router direct, it give me figures around the 200.
Now I have behind my provider router a Ubiquiti router and switch and the speeds are 1/4th of normal.
This is only the case for my Pi, a NAS, also on the same switch, does get the normal Internet speeds :-/

Code: Select all

[email protected]:~# speedtest-cli --server 3587 --secure --no-upload
Retrieving speedtest.net configuration...
Testing from Ziggo (xx.xx.xx.xx)...
Retrieving speedtest.net server list...
Retrieving information for the selected server...
Hosted by LeaseWeb (Haarlem) [26.84 km]: 904.579 ms
Testing download speed................................................................................
Download: 57.82 Mbit/s
Skipping upload test
[email protected]:~# 

I'm rocking a USG 3 and US-8-60W-to enable Flow Control, you have to go to the Unifi Controller, Devices, then click on the switch and at the right-side navigation, you have to go to the Config tab, Services and check "Enable flow control". Queue Changes, then apply the changes. Voila! Flow control enabled. This helped immensely with my home network and the Pi 3B+.

[Eichhorn18]

There is a suspected issue with Samba (and perhaps other network sharing mechanisms) that we haven't got to the bottom of yet, that may be unrelated.

The speedtest-cli result look exactly like flow control is not working effectively.

Is there any known issues with cifs as an alternative to samba?

Just for another data point, I have 800 Mbit/s service and i've connected a laptop with gigabit ethernet and gotten that delivery speed. The Raspberry Pi 3B+ on the same physical wire gives between 120 - 165 Mbit/s download, and upload between 100 - 220 Mbit/s.

[6by9]

There is a suspected issue with Samba (and perhaps other network sharing mechanisms) that we haven't got to the bottom of yet, that may be unrelated.

The speedtest-cli result look exactly like flow control is not working effectively.

Is there any known issues with cifs as an alternative to samba?

Just for another data point, I have 800 Mbit/s service and i've connected a laptop with gigabit ethernet and gotten that delivery speed. The Raspberry Pi 3B+ on the same physical wire gives between 120 - 165 Mbit/s download, and upload between 100 - 220 Mbit/s.

CIFS is a dialect of the SMB protocol that Samba implements.
We're fairly certain that has been resolved now anyway. It was stalling a single TCP connection rather than a speed issue.
https://github.com/raspberrypi/linux/issues/2449
https://github.com/raspberrypi/linux/issues/2482

Yours sounds like the standard type of flow control issue. You have a bottle-neck in the USB2 interface from the ethernet adapter to the Pi of a theoretical max of 480Mbit/s, but more realisitcally around 250Mbit/s. The adapter will be sending ethernet flow control pause frames when it backs up, but those only work over the local network. There is no mechanism to make an internet server back off other than rely on TCP's standard backoff/retry mechanisms.

[Eichhorn18]

CIFS is a dialect of the SMB protocol that Samba implements.
We're fairly certain that has been resolved now anyway. It was stalling a single TCP connection rather than a speed issue.
https://github.com/raspberrypi/linux/issues/2449
https://github.com/raspberrypi/linux/issues/2482

Yours sounds like the standard type of flow control issue. You have a bottle-neck in the USB2 interface from the ethernet adapter to the Pi of a theoretical max of 480Mbit/s, but more realisitcally around 250Mbit/s. The adapter will be sending ethernet flow control pause frames when it backs up, but those only work over the local network. There is no mechanism to make an internet server back off other than rely on TCP's standard backoff/retry mechanisms.

So I'm trying to transfer files through my local network, and scp from my windows machine is showing a max transfer speed of 11.5 MB/s.

What is required to check if flow control is turned on/off? I'm running an enterprise network through switches and some managed hubs.

[6by9]

So I'm trying to transfer files through my local network, and scp from my windows machine is showing a max transfer speed of 11.5 MB/s.

What is required to check if flow control is turned on/off? I'm running an enterprise network through switches and some managed hubs.

Code: Select all

[email protected]:~ $ sudo ethtool -a eth0
Pause parameters for eth0:
Autonegotiate:	on
RX:		on
TX:		on
RX negotiated:	on
TX negotiated:	on

on = good. off = bad.
Most managed switches will have options to enable/disable flow control. Unmanaged switches tend to have it enabled.

[Eichhorn18]

So I'm trying to transfer files through my local network, and scp from my windows machine is showing a max transfer speed of 11.5 MB/s.

What is required to check if flow control is turned on/off? I'm running an enterprise network through switches and some managed hubs.

Code: Select all

[email protected]:~ $ sudo ethtool -a eth0
Pause parameters for eth0:
Autonegotiate:	on
RX:		on
TX:		on
RX negotiated:	on
TX negotiated:	on

on = good. off = bad.
Most managed switches will have options to enable/disable flow control. Unmanaged switches tend to have it enabled.

Have done this today and all are reporting as 'on'. I tested my 3B+ several more times with speedtest-cli and getting average 145 Mbit/s download.
Seperatly I have copied an 800 MB file from the 3B+ to a network mounted folder on a windows machine, with gigabit ethernet. Time to copy was 63 seconds, giving a speed of approximately 14 MB/s or 110 Mbit/s. This seems far below the stated speed of the 3B+ of 300 Mbit/s max, but still you would expect better than this.

[drgeoff]

Seperatly I have copied an 800 MB file from the 3B+ to a network mounted folder on a windows machine, with gigabit ethernet. Time to copy was 63 seconds, giving a speed of approximately 14 MB/s or 110 Mbit/s. This seems far below the stated speed of the 3B+ of 300 Mbit/s max, but still you would expect better than this.

Copied from where on the 3B+? How fast can that place source data continuously?

[Eichhorn18]

Copied from where on the 3B+? How fast can that place source data continuously?

Copied from the SD card. I realize that in itself is an unfortunate bottleneck.

I have also written files that are stored in RAM, directly to a network mounted folder on a windows machine using CIFS. The transfer speed from RAM to the network folder (over a gigabit network and onto a gigabit enabled machine) was 30 MB/s, transferring 184MB of files in 6.13 sec.

Someone has suggested to me that running Stretch lite may have a different result. What do people think about that? I'm running Stretch Desktop at the moment.

[drgeoff]

Copied from where on the 3B+? How fast can that place source data continuously?

Copied from the SD card. I realize that in itself is an unfortunate bottleneck.

I have also written files that are stored in RAM, directly to a network mounted folder on a windows machine using CIFS. The transfer speed from RAM to the network folder (over a gigabit network and onto a gigabit enabled machine) was 30 MB/s, transferring 184MB of files in 6.13 sec.

Well, from RAM you get 30 Mbyte/s. That is 240 Mbit/s which is approaching the expected max rate of ethernet on a RPi 3B+.

[Eichhorn18]

Well, from RAM you get 30 Mbyte/s. That is 240 Mbit/s which is approaching the expected max rate of ethernet on a RPi 3B+.

It's true that is pretty decent. I wonder why the big difference (approximately 50%) for an internet connection that is supposed to give 800 Mbits/s on gigabit ethernet computers. What is the raspberry Pi doing for a speed test that it's not doing for a local network transfer--assuming the internet connection is not the limiting factor.

[ajp2k19]

Maybe I'm late to the party but here is what I have discovered so far...

https://www.snbforums.com/threads/slow- ... net.55114/

[6by9]

Maybe I'm late to the party but here is what I have discovered so far...

https://www.snbforums.com/threads/slow- ... net.55114/

So the same statement that has been made many times over in this thread then. Yes the Pi 3B+ requires ethernet flow control to be on to give reliable results. You can use "sudo ethtool -a eth0" to confirm whether it is on or off.
There was an intention to back off down to 100Mbit/s should flow control fail to be negotiated, but there hasn't been much progress on that.

[ajp2k19]

Maybe I'm late to the party but here is what I have discovered so far...

https://www.snbforums.com/threads/slow- ... net.55114/

So the same statement that has been made many times over in this thread then. Yes the Pi 3B+ requires ethernet flow control to be on to give reliable results. You can use "sudo ethtool -a eth0" to confirm whether it is on or off.
There was an intention to back off down to 100Mbit/s should flow control fail to be negotiated, but there hasn't been much progress on that.

Thanks, I wasn't sure there was any consenus on it. Now I have to figure out if I can enable it directly on my router, probably not...

[cdsgames]

Any news on the fix ??

[inShaneity]

I just purchased a 3B+ yesterday and I'm also experiencing slow speeds. My ISP is rated at 400Mbs up/20 down. My Pi is connected through the PoE hat and also has 1 HDD drive connected to it that's using Samba for network access. Seeing some issues in here about Samba, not sure about the PoE hat though. Running latest Stretch.

Before any changes and running speetest-cli, I was averaging about 30Mbs. Then I read up on enabling ethernet flow control. I have a Unifi 16 port PoE switch, so it was easy to find that setting and enable it. Now the speeds are averaging 125Mbs. If the max of this Pi is 300Mbs, then I'm still not even half way there.

Seeing people bouncing to different threads but I haven't found a consistent answer yet. Again, mostly concerned on maybe it being the PoE Hat in my case. Either way, I tried the Samba fix of turning off rx and tx, but I got an error that it was permitted to do that, so that didn't work.

What are my next steps from here, if there are any? Let me know if you need more information and I can provide that when I get home from work today.

[jamesh]

Not sure what to suggest. There's nothing wrong with the Pi I suspect, all the standard things have helpped, so there's something in the rest of the system going on to prevent higher speeds.

EDIT: Can you try powering it via a different mechanism to see if the that helps?

[inShaneity]

Not sure what to suggest. There's nothing wrong with the Pi I suspect, all the standard things have helpped, so there's something in the rest of the system going on to prevent higher speeds.

EDIT: Can you try powering it via a different mechanism to see if the that helps?

After further testing: Disabling Samba, removing the HDD, disabling WiFi, and removing the PoE hat, nothing changed. Speeds were still constant at around 125Mbs. I messed with the ethtool and changed it to 100 full, got worse speeds. Changed it back to 1000 and I was back at 125Mbs.

Then I randomly stumbled upon a post, not sure it if was in this thread, that said to try and update the FW using sudo rpi-update. The FW updated from 4.16.x to 4.19.37, I believe and it updated successfully. Running another speedtest-cli, increased my speeds by double! I was now seeing a constant 225Mbs - 250Mbs with the PoE Hat.

I still feel like the speeds should still be faster than that though. I'll keep doing some more tests...

[RPIgoodSBC]

This is a test gigabit ethernet on the new raspberry pi4 2Gb RAM...

[email protected]:~ $ sudo iperf3 -c xxx.xxx.x.xxx -R
Connecting to host xxx.xxx.x.xxx, port 5201
Reverse mode, remote host xxx.xxx.x.xxx is sending
[ 5] local yyy.yyy.y.yyy port 38716 connected to xxx.xxx.x.xxx port 5201
[ ID] Interval Transfer Bitrate
[ 5] 0.00-1.00 sec 112 MBytes 942 Mbits/sec
[ 5] 1.00-2.00 sec 112 MBytes 941 Mbits/sec
[ 5] 2.00-3.00 sec 112 MBytes 941 Mbits/sec
[ 5] 3.00-4.00 sec 112 MBytes 941 Mbits/sec
[ 5] 4.00-5.00 sec 112 MBytes 941 Mbits/sec
[ 5] 5.00-6.00 sec 112 MBytes 941 Mbits/sec
[ 5] 6.00-7.00 sec 112 MBytes 941 Mbits/sec
[ 5] 7.00-8.00 sec 112 MBytes 941 Mbits/sec
[ 5] 8.00-9.00 sec 112 MBytes 941 Mbits/sec
[ 5] 9.00-10.00 sec 112 MBytes 941 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.03 sec 1.10 GBytes 942 Mbits/sec 0 sender
[ 5] 0.00-10.00 sec 1.10 GBytes 941 Mbits/sec receiver

iperf Done.
[email protected]:~ $ uname -a
Linux raspberrypi 4.19.57-v7l+ #1244 SMP Thu Jul 4 18:48:07 BST 2019 armv7l GNU/Linux