I'm using a BrosTrend AXE3000 Wi‑Fi 6E USB adapter with Linux Mint DE 7 Gigi and kernel 6.12.101+deb13-amd64. On 2.4 GHz, the connection only reaches about 100 Mbps, occasionally a little higher, even though the adapter is advertised at up to 574 Mbps and my internet service provides up to 500 Mbps. A wired speed test from the router reaches over 500 Mbps, so the internet connection itself appears to be fine.
The adapter uses the MediaTek mt7921u driver and is plugged into a USB 3.2 Gen 1 port. Signal strength is excellent, and disabling Wi‑Fi power management made no noticeable difference. The system is fully updated. The wireless bit rate also fluctuates heavily, sometimes dropping from around 270 Mbps to 150 Mbps or even as low as 6 Mbps. There are roughly 8–10 devices on the network, although most are not actively using much bandwidth.
Switching to 5 GHz improves the speed to around 300 Mbps, with the reported link rate fluctuating between roughly 500 and 650 Mbps. I'm wondering whether this is a known mt7921u driver issue, whether the driver can be reloaded or reinstalled, and whether buying another adapter is likely to help.
2 Answers
The advertised 574 Mbps is a theoretical link rate, not the real download speed you should expect. Actual throughput is lower because of protocol overhead, interference, channel width, and other network activity. Still, a drop to around 100 Mbps with large rate fluctuations is unusually poor. The better 5 GHz results suggest that band is currently the more practical choice, while checking kernel updates and testing a different chipset with stronger Linux support may help more than repeatedly reinstalling the same driver.
The mt7921u driver has had well-known performance and stability problems on Linux, particularly with some USB adapters and 2.4 GHz connections. Since wired networking works normally, the fluctuating wireless rate and poor 2.4 GHz performance point more toward the driver or chipset support than your internet service. There may not be much to fix through reinstalling the driver if the same kernel module is installed again; updating to a newer kernel or waiting for improved driver support may be more effective.
That makes sense. I tried another adapter and saw nearly the same speeds, which suggests the shared driver support may be the limiting factor rather than the original hardware.
I switched to 5 GHz and now get about 300 Mbps, so I’ll probably use that for now while testing newer kernels or a better-supported adapter.