NVIDIA NVENC Lossless Support

The NVIDIA NVENC Lossless support feature enhances the Horizon Blast protocol by enabling hardware-accelerated HEVC 4:4:4 lossless encoding on modern NVIDIA GPUs. This feature provides superior image quality for graphically intensive applications while maintaining optimal performance through hardware acceleration.

When using NVIDIA NVENC lossless mode, the system uses HEVC Always Lossless encoding. If the hardware doesn’t support lossless mode or if Build-to-Lossless mode is selected, the system automatically falls back to Blast Codec Lossless.

Supported Lossless Modes

This feature enables the Always Lossless mode on the NVIDIA NVENC HEVC 4:4:4 codec. When enabled, every frame is encoded in lossless mode regardless of content or bandwidth conditions.

Note: Only HEVC 4:4:4 is supported for NVIDIA lossless encoding. H.264 4:4:4 lossless decoding is not GPU-accelerated by any current GPU, making it unsuitable for high-performance requirements. Lossless decoding is supported on NVIDIA and Intel GPUs, while AMD GPUs do not currently support HEVC 4:4:4.

Prerequisites

• Ensure that both Horizon Agent & Horizon Client version 2603 or later is installed.
• Supported operating systems include both Windows and Linux platforms that are compatible with Horizon 8.
• Windows Server 2022 or later is supported.
• To enable lossless mode on the client, the Horizon Client must have the Allow HEVC Decoding and Allow High Definition Color options enabled. See Enabling Client-Side Lossless Indicator

Note: The NVIDIA NVENC Lossless Indicator feature requires the 2603 client version. Older clients will still receive lossless video but will not display the indicator for HEVC 4:4:4 Lossless. In those clients, only Blast Codec Lossless mode displays the lossless indicator.

Agent-Side Hardware Requirements

For complete GPU compatibility information, see the NVIDIA Video Encode and Decode GPU Support Matrix.

Client-Side Hardware Requirements

Client devices must support HEVC 4:4:4 decoding

• NVIDIA GPUs: Any GPU from the Turing family (5th NVDEC generation) or newer supports HEVC 4:4:4 decoding
• Intel GPUs: Check Intel GPU support matrix for HEVC 4:4:4 decoding capability
• AMD GPUs: As of 2026, AMD has no GPUs supporting 4:4:4 decoding of any codec

Note: The Horizon Indirect Display Driver includes certain feature considerations. On some clients, hardware capabilities may not support decoding HEVC 4:4:4 Lossless bitstreams. In such cases, the system automatically falls back to BlastCodec Lossless to ensure continued functionality and a consistent user experience.

Network Requirements

NVENC lossless requires a strong and fast network connection. Depending on the type of screen content, resolution, and expected frame rate, the required network bandwidth may exceed 100 Mbps.

Enabling NVIDIA NVENC Lossless Mode

To activate lossless mode for NVIDIA NVENC, configure the corresponding setting on the agent machine:

• Windows Agent: To enable lossless mode, set the EncoderAlwaysLossless key to 1 in the HKEY_LOCAL_MACHINE\SOFTWARE\Omnissa\Horizon\Blast\Config folder in the Windows registry on the agent machine.

  • Alternatively, you can run the following command as an administrator reg add “HKLM\SOFTWARE\Omnissa\Horizon\Blast\Config” /v EncoderAlwaysLossless /t REG_SZ /d 1 /f

• Linux agent: Set the RemoteDisplay.alwaysLossless configuration option to true in /etc/omnissa/config.

Note: Configuration changes to lossless compression take effect immediately on Windows desktops. On Linux desktops, the changes are applied only after logging out and logging back in.