The question is: how write the app_config to make GPU projects and subprojects use only 90% of the capacity of the graphics card?

I could try something like this, but I do not know what value or number to write in the line "cpu_usage", the example is this:

<App_config>
<App>
<Name> name </ name>
<Max_concurrent> 1 </ max_concurrent>
<Gpu_versions>
<Gpu_usage> .90 </ gpu_usage>
<Cpu_usage> .1 </ cpu_usage>
</ Gpu_versions>
</ App>
</ App_config>


In this example the line "<max_concurrent> 1 </ max_concurrent>" would serve to be processed only one unit at a time, the line "<gpu_usage> .90 </ gpu_usage>" would only use 90% of the capacity of the Graphics card, what I do not know is what value to place on the line "cpu_usage> .1 </ cpu_usage" so that processor usage continues to be controlled by Boinc Manager.

Can you explain to me what value or number to place on the line "cpu_usage> .1 </ cpu_usage"
Thank you.

Gpu_usage does not work to limit the amount of GPU in the way you think.... it works out the "real fraction" each task is allowed to used 1/1, 1/2 etc., then runs the appropriate number of tasks, so with 1/2 you get two tasks running. This is mainly due to the fact that GPU applications are designed to occupy as many processing cores as they can. It is possible that with a max_concurrent value of 1 and a gpu_usage of 0.5 you would get one task running, but only use half the GPU processing cores, if you weren't doing any CPU tasks for the same project.
The Cpu_usage value is a "target" value, not an actual usage.