The GPU Memory Writes metric shows the total number of bytes written to memory by the GPU per frame. For example, GPU memory might be used when drawing to render targets.
This metric provides measurements for the whole system, not for a specific application being run.
If GPU Memory Writes is 640,000,000, it means that 640,000,000 bytes were written to memory by the GPU.
GPU Memory Writes are performed by multiple graphics operations. Some ways to reduce the number of GPU memory writes include:
- Reducing the number of rendering passes.
- Reducing the number of textures in the scene.
- Avoiding overdraw, where multiple draw calls render to the same pixel. Techniques to minimize overdraw include culling and drawing objects from front to back (taking advantage of depth-testing, which can abort the draw call from fully executing the entire pixel shader).
To help minimize GPU Memory Writes, capture a typical frame while the game is running. Use this frame as input to the Graphics Frame Analyzer, and try one or more of the following techniques:
- Use the 2x2 Textures experiment (in the Experiments tab) to see if textures are a bottleneck.
- Examine the use of textures by opening the Texture tab to see the texture size, format, and mip level.
- Use the Overdraw option in the Render Target Viewer to see which pixels are written to multiple times.
This metric is always a multiple of 64, since the Intel® HD Graphics 2500/4000 performs GPU Memory Writes transactions in terms of 64-byte cache lines.