The metric Texture Sampler Busy represents the percentage of time the texture sampler was busy handling texel fetch requests (that is, was either active or stalled).
On Intel® HD Graphics 2500/4000: to access this metric, you must explicitly enable the Intel® Graphics Performance Analyzers option in your BIOS settings:
Select System Agent (SA) Configuration
Select Graphics Configuration
Reboot your machine
If the BIOS on your system does not include the Intel® Graphics Performance Analyzers option, update your BIOS to the latest version from Intel. After completing your performance monitoring activity, we recommend that you disable the Intel® Graphics Performance Analyzers BIOS option and reboot your machine.
- If Texture Sampler Busy is 50, it means that texture sampler was active 50% of the rendering time for selected ergs.
- If Texture Sampler Busy is 0, it means that texture sampler was not used or time when it was active is very small.
When the Texture Sample Unit is running this might lead to execution unit stalls, especially if texture fetch latency does not occur in parallel with mathematical instructions (as the shader compiler attempts to optimized shader code to cover such latencies). Examine the GPU EUs Stalls metric to see amount of EUs stalls. If the percentage is high and the Texture Sampler Busy is close to 100%, most likely you have a texturing bottleneck. Try the 2×2 textures experiment in the Experiments Tab in the Intel® GPA Frame Analyzer to see if this is the case.