On Tue, Feb 06, 2024 at 07:58:40PM -0500, Peter King via talk wrote:
Hello all,
I have a computer located in the University of Toronto network which shows some odd network behaviour. For one, I have run speedtest-cli on it numerous times at various times of the day, and it consistently returns around 93Mbit upload/download. For comparison, a laptop in the same LAN seems to get 700Mbit, while a computer in a different part of the UofT network gets 900Mb/570Mb.
The NIC has a RealTek chip and uses the r8169 kernel module. Ethtool, which gives a live report, does list the card as running at 1Gb/s. But that sure isn't the speed I am getting.
This same slow computer also has problems if I reboot it remotely: most of the time it doesn't come up, though dmesg has the card detected. If I start from a cold boot rather than restart, it comes up correctly most of the time. In either case just typing in #netctl start <ethernet> starts it up just fine. I was trying to solve this problem and saw that there are several complaints along just these lines having to do with the r8169 module. Some people suggested downgrading to r8101 but that module is even older.
If the module isn't working well, that might account for the slower speeds.
Is there any way to tell? Obviously I can buy another NIC with a different chipset but don't really want to go to the trouble if there is an easier way to diagnose the difficulties.
All advice appreciated! Thanks.
Well if you search for it you will find well over a decade of people complaining about bed throughput on that chip. Some people claim it is a problem with the power management in the driver. I even saw one claiming a recent 6.5 kernel has finally fixed the performance for them. I remember the dlink DGE530T used to be popular because it used a marvell yukon chip with great performance (codeveloped with 3com). Then rev C1 came out. Same model name, same packaging, revision only difference. Used a rebranded realtek 8169. Different driver, much worse performance. Many people stopped specing the 530T since it went from good to garbage because someone made a cost saving revision. I remember it well, and not in a good way. I suggest finding another network card. Cards with an intel chip usually behave well. commit 93a3aa25933461d76141179fc94aa32d5f9d954a Author: Lennart Sorensen <lsorense@csclub.uwaterloo.ca> Date: Thu Jul 28 13:18:11 2011 +0000 r8169: Add support for D-Link 530T rev C1 (Kernel Bug 38862) The D-Link DGE-530T rev C1 is a re-badged Realtek 8169 named DLG10028C, unlike the previous revisions which were skge based. It is probably the same as the discontinued DGE-528T (0x4300) other than the PCI ID. The PCI ID is 0x1186:0x4302. Adding it to r8169.c where 0x1186:0x4300 is already found makes the card be detected and work. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=38862 Signed-off-by: Len Sorensen <lsorense@csclub.uwaterloo.ca> Signed-off-by: David S. Miller <davem@davemloft.net> -- Len Sorensen