Ozwel
Posts: 6
Joined: Tue Jul 10, 2018 6:54 pm

Rasp 3B+ download speed capped to 63Mbit/s :-/

Tue Jul 10, 2018 7:17 pm

Hi,

I installed Raspbian Stretch Lite on a brand new Rasp 3B+

When I perform a speedtest I always get the following speeds whatever the test server is:

Code: Select all

sudo speedtest-cli --server xxxxx
Hosted by xxxx [1.67 km]: 11.163 ms
Download: 63.52 Mbit/s
Upload: 244.83 Mbit/s
I first thought it was a bad microSD writing speed capping the network speed when downloading (therefore writing) but I tried this cmd too which allows the download without writting anything anywhere as you can guess:

Code: Select all

wget -O /dev/null http://bouygues.testdebit.info/100M.iso
--2018-07-10 19:02:01--  http://bouygues.testdebit.info/100M.iso
Resolving bouygues.testdebit.info (bouygues.testdebit.info)... 89.84.1.222, 2001:860:deff:1000::2
Connecting to bouygues.testdebit.info (bouygues.testdebit.info)|89.84.1.222|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 100000000 (95M) [application/x-iso9660-image]
Saving to: ‘/dev/null’

/dev/null           100%[===================>]  95.37M  6.12MB/s    in 16s

2018-07-10 19:02:17 (6.11 MB/s) - ‘/dev/null’ saved [100000000/100000000]
6.12MB/s = 49Mbit/s which does not look better in any way...

So here we are... my upload speed is ok because it matches my provider's max upload speed (fiber to the home with 1Gb down / 250Mb up) but my download speed seems capped whereas my fiber allows me to get 930Mbit/s when downloading from the exact same servers when using another computer from the LAN.
Important info: the raspberry is connected using a cat.6 cable (no WiFi).

Of course I don't expect the Raspberry 3B+ to offer a 1Gbit/s download speed in theory I should be able to get more than 100Mbit/s and maybe up to 300Mbit/s as the specs say, juste like my upload speeds has shown it's possible.


Thanks for clarifying.

mushu999
Posts: 29
Joined: Sun Aug 20, 2017 11:24 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 4:07 am

I assume you know that the 3B+ gigabit LAN shares the USB 2.0 buss and is thus capped at about 224 Mbps instead of the max 950 Mbps.

Interesting read here: https://www.jeffgeerling.com/blog/2018/ ... comparison

Also read this thread that suggests bad gigabit LAN cables cause problems and shows how to drop to 100 Mbps: viewtopic.php?t=207940

Finally, I have the Comcast 250 down/10 up package and here are my numbers from your same two speed tests:

Code: Select all

$ sudo speedtest-cli --server nnn
Retrieving speedtest.net configuration...
Testing from Comcast Cable (n.n.n.n)...
Retrieving speedtest.net server list...
Selecting best server based on ping...
Hosted by qqq (www) [18.49 km]: 17.936 ms
Testing download speed................................................................................
Download: 92.09 Mbit/s
Testing upload speed....................................................................................................
Upload: 11.97 Mbit/s
and

Code: Select all

$ wget -O /dev/null http://bouygues.testdebit.info/100M.iso
--2018-07-10 20:44:23--  http://bouygues.testdebit.info/100M.iso
Resolving bouygues.testdebit.info (bouygues.testdebit.info)... 89.84.1.222, 2001:860:deff:1000::2
Connecting to bouygues.testdebit.info (bouygues.testdebit.info)|89.84.1.222|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 100000000 (95M) [application/x-iso9660-image]
Saving to: ‘/dev/null’

/dev/null           100%[===================>]  95.37M  9.44MB/s    in 12s

2018-07-10 20:44:37 (7.75 MB/s) - ‘/dev/null’ saved [100000000/100000000]
...where 9.44MB/s is 75.52Mbps. Finally:

Code: Select all

$ uname -a
Linux pi-hole 4.14.52-v7+ #1123 SMP Wed Jun 27 17:35:49 BST 2018 armv7l GNU/Linux

ejolson
Posts: 3800
Joined: Tue Mar 18, 2014 11:47 am

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 5:43 am

Ozwel wrote:
Tue Jul 10, 2018 7:17 pm
So here we are... my upload speed is ok because it matches my provider's max upload speed (fiber to the home with 1Gb down / 250Mb up) but my download speed seems capped whereas my fiber allows me to get 930Mbit/s when downloading from the exact same servers when using another computer from the LAN.
Important info: the raspberry is connected using a cat.6 cable (no WiFi).
Almost surely you're missing flow control and the Pi is dropping packets upon receive because it can't keep up. The links listed in the previous post explore this problem in detail.

Where I'm currently living I'm lucky to get 5 Mbit down with 1 Mbit up. Such slow speeds really limit the kinds of innovation possible. Comcast 250 sounds better but the 10 Mbit up part still seems like early 90's technology. Would you mind describing using general terms in what city you can get 1 Gbit down with 250 Mbit up and for what cost?

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bensimmo
Posts: 4187
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 6:55 am

Did you update Raspbian Lite after you ran it the first time?
Yes you should be able to get 250 / 300Mbit/s
The initial version for the Pi3B+ had some Ethernet problems, the latest version hoped to solve them.
Depending on which you are using (though I do assume it's the newest, but you may have an older copy from before).
Anyway run
sudo apt update
sudo apt full-upgrade

Just to make sure you have the latest released firmware.
If so and the problem is still there report back :-)


Off to find the problem thread it's a long read.
edit.. it's a long read but it is *the topic*
viewtopic.php?f=63&t=208512 and if you've update you are at least 5 or 6 pages in ...

Ozwel
Posts: 6
Joined: Tue Jul 10, 2018 6:54 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 7:43 am

ejolson wrote:
Wed Jul 11, 2018 5:43 am
Where I'm currently living I'm lucky to get 5 Mbit down with 1 Mbit up. Such slow speeds really limit the kinds of innovation possible. Comcast 250 sounds better but the 10 Mbit up part still seems like early 90's technology. Would you mind describing using general terms in what city you can get 1 Gbit down with 250 Mbit up and for what cost?
Hi, I live in Paris (France). Fiber to the home (FTTH) is the selected solution to replace xDSL technologies (mainly ADSL for mass market, VDSL has arrived very late only 4-5 years ago and still remains rare) deployed since 2000-2001 in this country. FTTH is available for my home for 1 year now, FTTH is being deployed but all biggest cities in France have it now (a dozen). People in the country have connections like yours, it happens but they are really living in a distant place.

I don't know if prices will be interesting for you as phone and internet contracts in France have always been way cheaper than what you have in North America. I actually pay 35 EUR / month for my connection (including TV with free channels and land line with free calls to national fixed numbers) = 41 USD at the moment.

Ozwel
Posts: 6
Joined: Tue Jul 10, 2018 6:54 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 7:46 am

bensimmo wrote:
Wed Jul 11, 2018 6:55 am
Did you update Raspbian Lite after you ran it the first time?
Yes you should be able to get 250 / 300Mbit/s
The initial version for the Pi3B+ had some Ethernet problems, the latest version hoped to solve them.
Depending on which you are using (though I do assume it's the newest, but you may have an older copy from before).
Anyway run
sudo apt update
sudo apt full-upgrade

Just to make sure you have the latest released firmware.
If so and the problem is still there report back :-)


Off to find the problem thread it's a long read.
edit.. it's a long read but it is *the topic*
viewtopic.php?f=63&t=208512 and if you've update you are at least 5 or 6 pages in ...
Thanks for the link.
A full-upgrade does not upgrade anything (I perform dist-upgrade regularly and my stretch OS was downloaded and installed a few days ago).

I will check the link from page 5 in the next hours, hopefully there's an easy way to detect if my 3b+ is from the first copies and there's a way to ask for a replacement without writing a 3 pages letter :geek:

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bensimmo
Posts: 4187
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 7:57 am

Page 5 is just a guess, the latest Raspbian should have all their fixes in, especially since you update it.

apt full-upgrade
is the same as
apt-get dist-upgrade

Just apt is the newer way to do it, you get a prettier progress line :-)

Ozwel
Posts: 6
Joined: Tue Jul 10, 2018 6:54 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 8:05 am

Is the problem you said with Raspberry 3 b+ first copies "attached" to the hardware of is it something supposed to be resolved by an OS/software update?

I would prefer to avoid replacing the rasp :D

I read a bit about flow control but it seems it's something that has to be enabled on the router/switch. I have a Netgear R7000 which is not entry-level but I don't see anything referring to flow control. Should I enable something in raspbian by any chance?

drgeoff
Posts: 9914
Joined: Wed Jan 25, 2012 6:39 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 8:11 am

Ozwel wrote:
Wed Jul 11, 2018 7:46 am
if my 3b+ is from the first copies and there's a way to ask for a replacement without writing a 3 pages letter :geek:
You misread. There are no "first copies" of 3B+. The comment was about the software version not the hardware.

bensimmo wrote "The initial version for the Pi3B+ had some Ethernet problems, ...". Note the "for", not "of".

Ozwel
Posts: 6
Joined: Tue Jul 10, 2018 6:54 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 8:40 am

Alright so I digged a bit in regards of flow control.

What is my pastes told you my problem is from flow control? It seemed obvious to you.

I have just seen the rasp is directly connected to my ISP router which is not really providing a lot of network features. So I took the cable to connect it to the Netgear R7000, which I use as a WiFi bridge only (I turned off router features). And tadaaa my download speed is now 130Mbit/s

So there is something happening and it might be flow control. I still don't know what happened but it's already twice better.

My hope now is to achieve more provided that it is possible. I saw some test in the other thread showing higher speeds like >200Mbit/s so I'm still digging a bit more.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24129
Joined: Sat Jul 30, 2011 7:41 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Wed Jul 11, 2018 10:42 am

Ozwel wrote:
Wed Jul 11, 2018 8:40 am
Alright so I digged a bit in regards of flow control.

What is my pastes told you my problem is from flow control? It seemed obvious to you.

I have just seen the rasp is directly connected to my ISP router which is not really providing a lot of network features. So I took the cable to connect it to the Netgear R7000, which I use as a WiFi bridge only (I turned off router features). And tadaaa my download speed is now 130Mbit/s

So there is something happening and it might be flow control. I still don't know what happened but it's already twice better.

My hope now is to achieve more provided that it is possible. I saw some test in the other thread showing higher speeds like >200Mbit/s so I'm still digging a bit more.
This does look like a flow control problem, if it is off you get low throughput of around 60Mbits/s or so. Ensure it is turned on on your router. It usually is for home routers but some commercial ones do not have it one by default.

You should get between 200 and 300 Mbits/s if everything is working as expected.
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Ozwel
Posts: 6
Joined: Tue Jul 10, 2018 6:54 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Fri Jul 13, 2018 9:19 am

Hi,

Thanks for your help, I didn't manage to enable Flow control on my R7000 router, however, I learnt that my TP-Link switch (non-managable metal box) manages flow control by default. I tried to connect the Raspberry 3 B+ on it and tadaaaa, from 190 to 220 Mbit/s (stable) :D

Cheers

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24129
Joined: Sat Jul 30, 2011 7:41 pm

Re: Rasp 3B+ download speed capped to 63Mbit/s :-/

Fri Jul 13, 2018 10:54 am

Ozwel wrote:
Fri Jul 13, 2018 9:19 am
Hi,

Thanks for your help, I didn't manage to enable Flow control on my R7000 router, however, I learnt that my TP-Link switch (non-managable metal box) manages flow control by default. I tried to connect the Raspberry 3 B+ on it and tadaaaa, from 190 to 220 Mbit/s (stable) :D

Cheers
A quick Google for the R7000 and flow control didn't come up with anything. Which is surprising, I would expect it to be in there somewhere. But at least you are working at a better speed now!
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
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