problem with with reduced networkinginternet speed

**TheFu** · January 20th, 2021

I missed post#6 above. sorry. That has the most important information.
I did some testing using 5.4.x kernels between a few different systems here. They have a multitude of different NICs.

Both running 5.4.0.x

Code:

$ uname -r
5.4.0-62-generic

It is using an old Marvell NIC driver=skge. The other NIC inthat machine isn't good - realtek 8111h, I think. It was dropping packets.

Code:

[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.00  sec   513 MBytes   430 Mbits/sec                  receiver

Going between 2 other systems with the same kernel on both, using virtio drivers (VMs on the same physical machine):

Code:

[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  30.4 GBytes  26.1 Gbits/sec                  receiver

That tells me it isn't the kernel, but a driver or HW issue. I did some other testing with the 5.4.x kernels. All worked as expected. A 5.4.x kernel (i211 NIC) to 4.15.0-132-generic (usb3-gige-nic)

Code:

[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  1.07 GBytes   918 Mbits/sec                  receiver

All fine, as expected. That's going through 2 GigE switches too.

My main system has an Intel NIC, but it still runs 4.15.x with 16.04. The other 2 physical systems just got 5.4.x kernels last week, but they have really old NICs on the front network. They get over 500 Mbits/sec.

Sorry for the complexity. think it is a driver or hw issue, not the kernel. NIC drivers can be dependent on the kernel.
Can you isolate 1 NIC as the problem?

**robdavies** · March 7th, 2021

Sorry its taken time to reply, I've been doing testing and searching if others have been having the same problem with the same adapter (TPlink UE300). I did think that I'd get an email if there was an update on the forum, my mistake. I missed a couple of updates from other people that had posted. I appreciate that you have taken time to run tests for this.

I'll start with what problem others have found :

There is a kernel driver bug reported which has limited the download speed which is the same problem as I've been having. It uses driver r8152. Its located in <linux_source_directory>/drivers/net/usb/r8152.c
https://bugzilla.kernel.org/show_bug.cgi?id=205923

I download a kernel from kernel.org (5.10.11 at the time), applied the changed suggested on the above page, built and installed it, I got full broadband download speed 200Mb download 20Mb upload. At the time of this test, I still tested using speedtest rather than iperf. Shall I repeat this test using iperf? I did this as a test/trial, as I had installed 5.10.11 from https://kernel.ubuntu.com/~kernel-pp...line/v5.10.11/ and got slow network speed as usual. This driver issue hasn't been fixed in the mainline or stable kernel yet.

Second is the speed tests :

I am using iperf3, the server is the acer laptop with a 1Gb ethernet adapter running xubuntu 20.04 lts. I had run a broadband speedtest and its getting 600Mb download on 600Mb/40Mb broadband, so I know the adapter will manage at least 600Mb. I also did a broadband test on this acer laptop using the UE300 adapter via usb3 and got 600Mb download, knowing that this adapter will perform at least 600Mb. Since my last post, my broadband has been upgraded to 600/40Mb (only mentioned it as my previous tests mentioned it as 200Mb)

I has to read and learn more about iperf. Any previous tests I had run were without -R option, so were upload speeds only. Sorry about that, I had missed that one.

The following tests were run on a Dell d830 running Xubuntu 20.10 with a TPlink UE300 usb ethernet adapter. Since my last posting, I had upgraded it from 20.04 to 20.10

default kernel on 20.10:
kernel 5.8.0-44-generic : download 60 Mb upload 260 Mb

The following kernels downloaded from ubuntu ppa, installed and speed tests run with iperf3 :
kernel 5.3.18 : download 310 Mb upload 260 Mb
kernel 5.4.0 : download 60 Mb upload 260 Mb
kernel 5.10.8 : download 60 Mb upload 260 Mb
kernel 5.10.10 : download 60 Mb upload 260 Mb
kernel 5.10.11 : download 60 Mb upload 260 Mb
kernel 5.10.20 : download 60 Mb upload 260 Mb
kernel 5.11.0 : download 60 Mb upload 260 Mb
kernel 5.11.3 : download 60 Mb upload 260 Mb

compiled kernel from kernel.org broadband speed using speedtest.net. Shall I run this test again using iperf? I will need to recompile this kernel again as I have removed it during a clearup of the kernels I have installed.
kernel 5.10.11 : download 220Mb upload 20Mb

Is there anything else I need to run/test? Is this enough to go on?

Thanks,
Rob

**praseodym** · March 7th, 2021

Haven't read through, but: What hardware is in use? Please show

Code:

lspci -nnk | grep -iA2 net
lsusb
lsmod

**Doug S** · March 7th, 2021

If I understand correctly, then there is nothing left to do. There is already an upstream bug report. The problematic commit is already known. The solution is already known. So, the question becomes why hasn't an upstream patch been submitted correcting the problem?