Different kernel, different download speed

Hello everyone, I have been using CachyOS on my laptop for quite some time and everything works very well. The only thing I can’t explain is why with kernel 6.9.3 my speed tests seem “throttled” and on average they give a result of 750 Mbps while with the LTS 6.6.32 kernel the speed tests return average values of 1.4 Gbps. I also noticed that the broadcom modules are also loaded while I have a “Killer AX1650i” detected as “Intel® Wi-Fi 6 AX203” and the bluetooth as “Intel Corp. AX201 Bluetooth”. With the LTS 6.6.32 the firmware that is loaded is 83 while with the 6.9.3 it is 89…

❯ sudo dmesg | grep iwlwifi
[    7.629204] iwlwifi 0000:00:14.3: Detected crf-id 0x1300504, cnv-id 0x80400 wfpm id 0x80000030
[    7.629244] iwlwifi 0000:00:14.3: PCI dev 51f0/1652, rev=0x370, rfid=0x10a100
[    7.635952] iwlwifi 0000:00:14.3: TLV_FW_FSEQ_VERSION: FSEQ Version: 0.0.2.42
[    7.636243] iwlwifi 0000:00:14.3: loaded firmware version 89.e9cec78e.0 so-a0-hr-b0-89.ucode op_mode iwlmvm
[    7.713159] iwlwifi 0000:00:14.3: Detected Intel(R) Wi-Fi 6 AX203, REV=0x370
[    7.721497] iwlwifi 0000:00:14.3: WRT: Invalid buffer destination
[    7.824290] iwlwifi 0000:00:14.3: WFPM_UMAC_PD_NOTIFICATION: 0x20
[    7.824299] iwlwifi 0000:00:14.3: WFPM_LMAC2_PD_NOTIFICATION: 0x1f
[    7.824306] iwlwifi 0000:00:14.3: WFPM_AUTH_KEY_0: 0x90
[    7.824314] iwlwifi 0000:00:14.3: CNVI_SCU_SEQ_DATA_DW9: 0x10
[    7.824371] iwlwifi 0000:00:14.3: Detected RF HR B5, rfid=0x10a100
[    7.825423] iwlwifi 0000:00:14.3: RFIm is deactivated, reason = 4
[    7.890326] iwlwifi 0000:00:14.3: base HW address: 4c:03:4f:f5:76:c5
[    8.158586] iwlwifi 0000:00:14.3: WRT: Invalid buffer destination
[    8.256622] iwlwifi 0000:00:14.3: WFPM_UMAC_PD_NOTIFICATION: 0x20
[    8.256632] iwlwifi 0000:00:14.3: WFPM_LMAC2_PD_NOTIFICATION: 0x1f
[    8.256640] iwlwifi 0000:00:14.3: WFPM_AUTH_KEY_0: 0x90
[    8.256649] iwlwifi 0000:00:14.3: CNVI_SCU_SEQ_DATA_DW9: 0x10
[    8.257742] iwlwifi 0000:00:14.3: RFIm is deactivated, reason = 4
[    8.326606] iwlwifi 0000:00:14.3: Registered PHC clock: iwlwifi-PTP, with index: 0
[    8.360903] iwlwifi 0000:00:14.3: WRT: Invalid buffer destination
[    8.458742] iwlwifi 0000:00:14.3: WFPM_UMAC_PD_NOTIFICATION: 0x20
[    8.458752] iwlwifi 0000:00:14.3: WFPM_LMAC2_PD_NOTIFICATION: 0x1f
[    8.458760] iwlwifi 0000:00:14.3: WFPM_AUTH_KEY_0: 0x90
[    8.458767] iwlwifi 0000:00:14.3: CNVI_SCU_SEQ_DATA_DW9: 0x10
[    8.460064] iwlwifi 0000:00:14.3: RFIm is deactivated, reason = 4

~
❯ lsusb | grep Bluetooth
Bus 003 Device 004: ID 8087:0026 Intel Corp. AX201 Bluetooth

~
❯ lspci -nnkv | sed -n '/Network/,/^$/p'
0000:00:14.3 Network controller [0280]: Intel Corporation Alder Lake-P PCH CNVi WiFi [8086:51f0] (rev 01)
        Subsystem: Rivet Networks Dual Band Wi-Fi 6(802.11ax) Killer AX1650i 160MHz 2x2 [Cyclone Peak] [1a56:1652]
        Flags: bus master, fast devsel, latency 0, IRQ 16, IOMMU group 10
        Memory at 6105274000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: <access denied>
        Kernel driver in use: iwlwifi
        Kernel modules: iwlwifi, wl


~

Waiting for some suggestions, I thank you for your attention.

We have in the latest Kernel BBR3 patched.
You can change via sysctl to the default algorithm “cubic”. Maybe this helps.

Hi Ptr,
thanks for the suggestion but the same configuration on different kernels leads to these different results :frowning:
I also tried the core version of kernel and got the same result.

So, if I understand correct, this is also present on the default kernel?

Yes, I apologize but only now I thought of trying the default version as well. To be precise, I tried:

cachyos-v3/linux-cachyos 6.9.3-2
core/linux 6.9.3.arch1-1

cachyos-v3/linux-cachyos-lts 6.6.32-1
core/linux-lts 6.6.32-1