IPVanish Turns On OpenVPN High-Speed Mode (DCO) on Windows — Up to 196% Faster
IPVanish has enabled OpenVPN High-Speed Mode (DCO) in its Windows client, promising up to 196% faster OpenVPN speeds with the same audited security. Here's what DCO does, the measured gains, how to turn it on, and the caveats — it's Windows-only and won't run with Scramble.
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IPVanish has shipped one of the more meaningful VPN upgrades of the year: on July 13, 2026 it turned on OpenVPN High-Speed Mode (DCO) in its Windows client. The pitch is simple and, for once, backed by hard numbers — you keep OpenVPN's rock-solid security, but with up to 196% faster speeds than the old Windows implementation. Here's what it actually does, the measured gains, and the honest caveats before you flip it on.
What OpenVPN and DCO are
OpenVPN is the open-source, independently audited VPN protocol that's been the industry's trusted default for years. It's secure, stable and well-understood — which is exactly why it's stuck around. Its one persistent weakness has been raw speed: historically OpenVPN carried a performance penalty compared with newer protocols like WireGuard, because all that encryption work happened in user space.
Data Channel Offload (DCO) is what closes that gap. Instead of shuffling encrypted OpenVPN data through user space, DCO processes it directly in the operating system's kernel space. That removes most of the overhead that made OpenVPN feel slow — so you get world-class, audited security running at speeds that finally hold up for everyday use.
The speed numbers
IPVanish says its internal testing — run across multiple days and server locations — produced the following average improvements versus the previous Windows client:
| OpenVPN mode | Improvement | Best for |
|---|---|---|
| UDP download | +196% | Raw performance — streaming, big downloads |
| TCP download | +131% | Less stable / restrictive networks |
| UDP upload | +101% | Uploads, backups, video calls |
| TCP upload | +34% | Reliability over unstable links |
If you just want the fastest result, OpenVPN UDP is the standout. TCP modes trade some speed for resilience, which helps on flaky or heavily filtered connections.
A quieter security and connection bonus
DCO isn't the only change. On Windows, IPVanish also upgraded the OpenVPN cipher from AES-256-CBC to AES-256-GCM. GCM is a modern authenticated-encryption mode that's both faster and more robust — and the switch is automatic, so there's nothing to configure. IPVanish also reports connection times cut by roughly 32% versus the old Windows client, so you're online quicker as well as faster once connected.
Who benefits
- Streamers and gamers who want low latency and high throughput without dropping to a less-audited protocol.
- Anyone moving large files — backups, uploads, big downloads — where OpenVPN used to be painfully slow.
- Laptop users, remote workers and travelers. Because DCO offloads work to the kernel, it lowers CPU usage, which means less heat and better battery life on the road.
- Privacy-conscious users who wanted OpenVPN specifically but couldn't stomach the speed cost. That trade-off is largely gone.
The best part: it's 100% free for all new and existing IPVanish Windows users. There's no add-on, no premium tier — it just makes the plan you already have better.
How to enable High-Speed Mode (DCO)
- Update to the latest IPVanish Windows app (DCO ships in the current release).
- Open the app and go to Settings in the left-hand navigation.
- Open the Protocol tab.
- Set Active Protocol to OpenVPN.
- Toggle on High-Speed Mode (DCO).
That's it — reconnect and you're running the accelerated path.
Honest caveats
No upgrade is all upside, and IPVanish's is refreshingly specific about the limits:
- Windows only, for now. DCO is currently exclusive to the Windows client. macOS, mobile and other platforms don't have it yet.
- Not compatible with OpenVPN Scramble. If you rely on IPVanish's Scramble feature to disguise VPN traffic and bypass VPN blocking (in restrictive networks or regions), you can't run Scramble and DCO at the same time. You'll have to choose one or the other depending on whether your priority is speed or getting through a block.
- "Up to 196%" is a best case. That headline figure comes from IPVanish's own testing under favorable conditions (UDP downloads, good servers). Real-world gains vary with your server choice, distance, ISP and local network — expect a solid improvement, but don't treat 196% as a guarantee.
Bottom line
OpenVPN High-Speed Mode (DCO) is a genuinely useful upgrade, not just marketing: kernel-space processing plus the AES-256-GCM cipher jump takes OpenVPN's long-standing speed weakness and largely erases it, at no extra cost to Windows users. If you were sticking with OpenVPN for its audited, battle-tested security but wincing at the speeds, this is the update that makes it a first-choice protocol again. Just remember it's Windows-only and won't run alongside Scramble — beyond that, there's little reason not to switch it on.
