Add Wireguard performance section

FAQ/Wireguard.md

@@ -3,3 +3,43 @@
 Wireguard is implemented using imported packages from [git.zx2c4.com/wireguard-go](https://git.zx2c4.com/wireguard-go).
 
 It should be using the Kernel wireguard module if it is present and fallback to a Go user space Wireguard implementation otherwise, to maximize compatibility and performance.
+
+## Performance
+
+Wireguard is often known as *so much faster* than OpenVPN. Let's find out!
+
+- Gluetun `v3.24.0` is used
+- The Mullvad VPN service provider is used
+- Gluetun is connected to the closest VPN server. This is to better measure the performance of the protocol, instead of the various bandwidth bottlenecks on a further away server.
+- The following command is used to measure bandwidth performance:
+
+    ```sh
+    docker run -it --rm --network=container:gluetun alpine:3.14 /bin/sh -c "apk add speedtest-cli && speedtest-cli"
+    ```
+
+- Two machines were tested:
+    1. Docker Desktop on WSL2 on a Windows host
+        - 24 threads cpu (amd 5900x)
+        - Running on Docker desktop with wsl2 on a windows host
+    2. Linux host
+        - 12 threads cpu (amd 2600x)
+        - Running on an Arch Linux host with recent kernel
+
+Here comes the disappointment bomb...
+
+| Machine | Protocol | Download | Upload | Download diff vs other protocol |
+| --- | --- | --- | --- | --- |
+| Windows host | OpenVPN | `299.24` | `463.69` | +0.23% |
+| Windows host | Wireguard | `298.55` | `493.49` | -0.23% |
+| Linux host | OpenVPN | `645.91` | `481.25` | -4% |
+| Linux host | Wireguard | `673.37` | `561.28` | +4.2% |
+
+Conclusions:
+
+- Docker desktop on Windows sucks network performance wise 😆
+- Wireguard is only up to 4.2% faster than OpenVPN.
+
+Further investigations:
+
+- [ ] Does Wireguard have a bigger impact on low power devices such as Raspberry Pis?
+- [ ] Does Wireguard have a bigger impact on many cores and low single thread performance CPUs?