Realtek RTL8156 2.5G Chips + RTL8153 To Be Supported By Linux 5.13

[ix900]

limited to ~1.70 Gbits/sec. Another machine with a 10gbit NIC can pull ~7 Gbits/sec from it so I know the problem isn't with the server. I also tested on Windows 10 and see the same issue there.

Is that same drive write speeds on both? Drive cache size also? No heat throttling? How about has trim been running?

its easy to miss some other problem.

[ahrs]

Your result is 2.45GBit/s, did you change the MTU? If yes did you do it on both sides?

Both are using an MTU of 8174 and this is advertised by the IPv6 router-advertisement daemon and DHCP. Why 8174 you ask? It's a compromise, if you select 8K jumbo frames in Windows this is the MTU you get and in a sample-size of "number of things I have connected to Ethernet" everything seems to support it (I have some devices that will not accept an MTU of 9000).

[zamadatix]

Will this actually support 2.5gbit download? My motherboard has an onboard 2.5gbit Realtek adapter (05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller) and I can max it out when uploading to my file server but downloads are limited to ~1.70 Gbits/sec. Another machine with a 10gbit NIC can pull ~7 Gbits/sec from it so I know the problem isn't with the server. I also tested on Windows 10 and see the same issue there.

$ iperf3 -c 2001:DB8::11
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 2.85 GBytes 2.45 Gbits/sec 0 sender
[ 5] 0.00-10.00 sec 2.85 GBytes 2.45 Gbits/sec receiver

$ iperf3 -c 2001:DB8::11 -t 60 -R
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-60.00 sec 11.6 GBytes 1.66 Gbits/sec 167126 sender
[ 5] 0.00-60.00 sec 11.6 GBytes 1.66 Gbits/sec receiver

(7/10)*2.5 = 1.75

I think you have something else going on with the box or how you're connecting them or something - each is ~30% underperforming. Trying setting the MTU to 9000 and doing -P 4 and see if the number is any different.

Most likely guess is the congestion control algorithm or buffer sizes on the server. If they aren't directly connected try that.

[numacross]

Will this actually support 2.5gbit download? My motherboard has an onboard 2.5gbit Realtek adapter (05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller) and I can max it out when uploading to my file server but downloads are limited to ~1.70 Gbits/sec. Another machine with a 10gbit NIC can pull ~7 Gbits/sec from it so I know the problem isn't with the server. I also tested on Windows 10 and see the same issue there.
[/CODE]

I have a 8125 (PCI\VEN_10EC&DEV_8125&SUBSYS_E0001458) as well and it works fine under both Windows and Linux:

[ ID] Interval Transfer Bandwidth
[ 4] 0.00-10.00 sec 2.76 GBytes 2.37 Gbits/sec sender
[ 4] 0.00-10.00 sec 2.76 GBytes 2.37 Gbits/sec receiver

[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 2.76 GBytes 2.37 Gbits/sec 0 sender
[ 4] 0.00-10.00 sec 2.76 GBytes 2.37 Gbits/sec receiver

Your result is 2.45GBit/s, did you change the MTU? If yes did you do it on both sides?

[stormcrow]

Will this actually support 2.5gbit download? My motherboard has an onboard 2.5gbit Realtek adapter (05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller) and I can max it out when uploading to my file server but downloads are limited to ~1.70 Gbits/sec. Another machine with a 10gbit NIC can pull ~7 Gbits/sec from it so I know the problem isn't with the server. I also tested on Windows 10 and see the same issue there.

$ iperf3 -c 2001:DB8::11
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 2.85 GBytes 2.45 Gbits/sec 0 sender
[ 5] 0.00-10.00 sec 2.85 GBytes 2.45 Gbits/sec receiver

$ iperf3 -c 2001:DB8::11 -t 60 -R
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-60.00 sec 11.6 GBytes 1.66 Gbits/sec 167126 sender
[ 5] 0.00-60.00 sec 11.6 GBytes 1.66 Gbits/sec receiver

On a guess, the RTL NIC is just "2.5 Gb class" rather than 2.5 in truth. Realtek cuts a lot of corners and it wouldn't surprise me that some part of that chain was cut to save a couple of cents. RTL shenanigans in the past include inadequate ring buffers, or shared bus lines, or something else that makes it cheap, but means it'll never actually reach full bandwidth. Assuming I'm not missing something from being groggy in the morning and on my first round of caffeine.

[ahrs]

Will this actually support 2.5gbit download? My motherboard has an onboard 2.5gbit Realtek adapter (05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller) and I can max it out when uploading to my file server but downloads are limited to ~1.70 Gbits/sec. Another machine with a 10gbit NIC can pull ~7 Gbits/sec from it so I know the problem isn't with the server. I also tested on Windows 10 and see the same issue there.

$ iperf3 -c 2001:DB8::11
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 2.85 GBytes 2.45 Gbits/sec 0 sender
[ 5] 0.00-10.00 sec 2.85 GBytes 2.45 Gbits/sec receiver

$ iperf3 -c 2001:DB8::11 -t 60 -R
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-60.00 sec 11.6 GBytes 1.66 Gbits/sec 167126 sender
[ 5] 0.00-60.00 sec 11.6 GBytes 1.66 Gbits/sec receiver

[angelsl]

The article is a bit vague. RTL8153 and RTL8153B have both been supported for a long time—since Jul 2015 and Jun 2017 respectively. What's new is support for RTL8153C (and the 8156 series).

[CTTY]

Nice to see Realtek providing more support in the kernel. They have a lot of out-of-tree modules with bugs and stuff. I'd like to see them integrated and working.

[Schugy]

My Notebook has no LAN port and now with driver support I can actually buy one of these external adapters.

[phoronix]

Phoronix: Realtek RTL8156 2.5G Chips + RTL8153 To Be Supported By Linux 5.13

Realtek has contributed support for the RTL8153 and RTL8156 Ethernet chipsets to their "r8152" USB network driver for the upcoming Linux 5.13 cycle...

https://www.phoronix.com/scan.php?page=news_item&px=Realtek-RTL8153-RTL8156-Linux