openxr-performance.md

title	OpenXR performance
description	Learn how to debug the GPU performance of your OpenXR mixed reality applications.
author	thetuvix
ms.author	alexturn
ms.date	2/28/2020
ms.topic	article
keywords	OpenXR, Khronos, BasicXRApp, DirectX, native, native app, custom engine, middleware, performance, optimization, GPU debugging, RenderDoc, PIX

OpenXR performance

On HoloLens 2, there are a number of ways to submit composition data through xrEndFrame, which can result in post-processing and noticeable performance penalties.

To avoid poor performance, submit a single XrCompositionProjectionLayer with the following characteristics:

• Use a texture array swapchain
• Use the primary color swapchain format
• Use the recommended view dimensions
• Don't set the XR_COMPOSITION_LAYER_UNPREMULTIPLIED_ALPHA_BIT flag
• Set the XrCompositionLayerDepthInfoKHR minDepth to 0.0f and maxDepth to 1.0f

For better performance, consider:

• Using the 16-bit depth format
• Making instanced draw calls