Operating a VPN on a NAS results in transfers around 3 to 4MB per second.
Operating a VPN on a NAS results in transfers around 3 to 4MB per second.
I’ve been trying to configure my QNAP NAS as a VPN server for remote access to large image files. After experimenting over the weekend, I managed to set up the QVPN app using OpenVPN and connect from my Windows 10 PC at home. However, I’m experiencing very slow download speeds—around 3–4 MB/s—and only slightly faster uploads (8–12 MB/s) on my Windows machine after mapping a network drive. The NAS’s CPU stays under 20% during testing, but both my home and work connections are Gigabit down with 100 Mbps upload. I’m not sure what went wrong. Should I switch to L2TP/Ipsec or WireGuard instead of OpenVPN? Thanks, Dave.
Wireguard should improve speed, though it might not convert 3-4 Mbps into a full 100 Mbps. If your Celeron lacks hardware encryption, that could be the problem—unless you're comfortable with QNAP configurations. It might be worth testing WireGuard since setup is very simple.
Is this a multi-core processor? Check performance on each core separately instead of just overall usage. I think you're likely dealing with a single-threaded task. Even if the overall percentage looks low, only one core is active, so it's still hitting the CPU's maximum. ~Note: If your file size is 100 Mbit and you receive 12 MB/s from the server, you're at full capacity. 100 Mbps equals 12.5 MBps. The server's upload speed (your download) seems slower—around 3-4 MB/s. Encryption might require more processing than decryption, which could be the reason.
I was focusing on the numbers in megabits per second, yet if the person claims 100 Mbps upload but only sees 8–12 MBps, they’re likely at full capacity. I thought it might be 100 Mbps and 8–12 MBps (about 1 MBps), but I could have misunderstood. We should ask for clarification from OP.
You're absolutely correct—the upstream connection is the limiting factor in both directions, capping at 100 megabits, which equals about 12.5 MegaBytes after accounting for overhead (up to 20% for OpenVPN). Reviewing CPU usage shows no single core is under stress, but some hardware acceleration might be pushed to its limit. I recommend upgrading to symmetrical gigabit internet for the office. Thanks!