I have added a GPU but the project doesn't use it
From BOINC Wiki
When you add a GPU, you need some requirements for BOINC to use it:
- Drivers from the GPU manufacturer.
- A BOINC project capable of using this GPU.
- Telling the project & BOINC that it's all right to use the GPU.
Drivers
A GPU capable BOINC project
Tell a project to use the GPU