Package: linux-image-6.12.0-1-amd64
Version: 6.12.0-1
Severity: important
Hello,
I am reporting a network performance regression with the Realtek RTL8125
(PCI ID [10ec:8125]) when moving from Debian 12 (Bookworm, kernel 6.1 LTS)
to Debian Trixie (kernel 6.12).
- On Debian 12 with linux-image-6.1.0-26-amd64, throughput is ~838 Mb/s
on a gigabit Ethernet link (expected value).
- On Debian 13 with linux-image-6.12.0-1-amd64, the link still negotiates
"Speed: 1000Mb/s, Duplex: Full" correctly, but actual throughput drops
to ~300 Mb/s.
- I tested with both the in-kernel `r8169` driver and the external
`r8125-dkms` package (and also Realtek’s own source release).
The performance issue persists.
Relevant output:
lspci -nnk | grep -A3 -i net
05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8125
2.5GbE Controller [10ec:8125] (rev 05)
Subsystem: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE
Controller [10ec:0123]
Kernel driver in use: r8125
Kernel modules: r8169, r8125
ethtool enp5s0 (on Trixie):
Speed: 1000Mb/s
Duplex: Full
Link detected: yes
Speed test results:
- Debian 12 (6.1): ~838 Mb/s (iperf3/wget)
- Debian 13 (6.12): ~300 Mb/s
This looks like a regression in kernel 6.12 for RTL8125.
Thanks.
