Choosing Compatible Wi-Fi Hardware For Linux: A Guide

Determining Your Needs

When choosing a Wi-Fi card for Linux, first determine what kind of functionality you need. Consider the following factors:

Speed – If you simply need basic internet connectivity, a lower-speed 300Mbps card may suffice. For faster file transfers and streaming, consider dual-band 450Mbps+ cards.
Single vs. Dual Band – Lower-end cards are typically single 2.4GHz band. Dual-band cards support both 2.4GHz and 5GHz bands for reduced interference and more available channels.
Desktop vs. Laptop – Desktop PCIe cards generally offer better performance and connectivity than laptop mini PCIe cards.
USB vs. Internal – USB Wi-Fi adapters are portable but may have antenna limitations affecting speed and signal strength.

Researching Chipsets

The chipset is the key component that handles communication between a Wi-Fi card and Linux. Some chipsets have native open-source Linux drivers while others require closed-source third party drivers. Research what chip a card uses before purchasing it. Common Wi-Fi chipset manufacturers include:

Atheros – Excellent Linux support with open ath9k drivers. Mid-range to high speeds.
Realtek – Hit or miss Linux compatibility requiring rtl8812au/rtl8821au driver installation. Low to mid-range cards.
Broadcom – Typically requires closed-source third party b43, b43legacy or broadcom-wl drivers. Low to high end cards.
Intel – Intel Wi-Fi chipsets like the Wireless-AC 9260 have good Linux support with the open-source iwlwifi driver. Mid to high speeds.

Checking Linux Hardware Compatibility Lists

To simplify your search, consult sites like the Linux Foundation’s WiFiDeviceList at https://wiki.linuxfoundation.org/wifi/start that index cards and chipsets known to work with Linux. Distro-specific sites like https://help.ubuntu.com/community/WifiDocs/WirelessCardsSupported for Ubuntu are also helpful. These provide user reports on various Wi-Fi hardware compatibilities.

Table of Contents

Intel and Atheros Cards – Out of the Box Support

Intel Wi-Fi chipsets with model numbers like Wireless-AC 9260 and Atheros chipsets in the ath9k/ath10k family have open Linux drivers built into the kernel, meaning they work out of the box on most Linux distributions without any driver installation needed. This makes them the most hassle-free option. Both offer decent mid-range to high speed cards at reasonable prices. For PCIe, USB and mini PCIe form factors, look for cards using Intel 9260/9460/9560 chipsets or Atheros QCA9377/981x/988x chipsets.

Realtek – Additional Driver Installation

Realtek based Wi-Fi cards can work on Linux but often require installing closed-source rtl8812au or rtl8821au drivers from GitHub. The stability and performance of these drivers can vary between kernel revisions. USB Wi-Fi adapters with detachable antennas using the RTL8812BU chipset are popular due to support from the rtl8812au driver. For PCIe and mini PCIe, look for RTL8821CE or RTL8822BE chips. Verify someone else has gotten the exact model working before purchase if going the Realtek route.

Broadcom – Using Alternate Drivers

Broadcom Wi-Fi chips have historically had poor Linux support, requiring closed-source third party drivers. Older Broadcom 43xx chips can use the open b43 legacy driver. For newer Broadcom chips, options like the closed-source broadcom-wl driver or open-source brcmfmac driver are alternatives. Support and compatibility for these can vary between kernel versions. Broadcom chips can offer high speed cards at low costs but likely require tinkering to work properly on Linux.

USB Wi-Fi Adapters – Pros and Cons

USB Wi-Fi adapters are easy to install and move between systems, but may demonstrate lower speeds, signal strength and driver compatibility versus PCIe cards due to antenna and chip limitations. Check that a USB adapter explicitly supports “AP” or “Master” mode if you need to use it as a Wi-Fi hotspot. Modern adapters using AX200 or AX210 chips from Intel or RTL8812BU from Realtek can offer fairly reliable mid-range performance on Linux.

Testing Wi-Fi Cards Before Purchase

If still uncertain about compatibility, purchase Wi-Fi cards from retailers with good return policies and test in Linux before permanent installation. Boot a live Linux environment like an Ubuntu or Fedora live USB stick on the target computer, insert the Wi-Fi card in an available PCIe/mini PCIe slot or connect the USB adapter, and verify visible wireless networks and internet connectivity. This provides a simple way to quickly validate Linux compatibility without hassles.

Troubleshooting Incompatible or Poorly Performing Cards

If a Wi-Fi card isn’t working properly in Linux, first update to the latest kernel, wireless driver and firmware packages in case support was recently added. In terminal, enter dmesg | grep firmware after inserting the card to check for driver issues. Search Linux forums to see if others have encountered and solved the problem. As a last resort, compiling and manually installing the latest bleeding edge version of a driver from source code may resolve otherwise incompatible cards. There are also options like NDISWrapper to get Windows drivers functioning on Linux.

Optimizing Settings for Your Card and Environment

Once a compatible Wi-Fi card is installed and working, optimize settings for the specific card chipset and environment through:

Using a Wi-Fi analyzer to determine congestion on channels and switch to less crowded 5GHz channels if possible.
Moving computer or antennas nearer to the access point to improve signal strength.
Testing different antennas to compare signal strength and throughput.
Adjusting txpower settings if signal strength is very high or low.
Enabling hardware offloading/TCP segmentation offloading for supported chipsets.

Proper optimization can significantly improve wireless network speeds and reliability.