Amicable GPU is a tough cookie. The older 10*20 app, people were running up to 16 tasks at a time to get the GPU utilized 100%. No more. 10*21 app is a resource hog.
- First of all, one task will now send your card to 100% usage.
- Secondly, each task requires 8GB of SYSTEM RAM. Make sure your page file is enabled!
- Third, each task will use a lot of CPU upfront, calculating the 8GB of Primes that go into RAM, then CPU usage drops dramatically. Leave at least one thread free per task.
- Fourth, because of the third note above, processor performance matters for this GPU project.
I used kernel size 23 for my much newer Nvidia cards, and kernel size 21 for my poor old R9-280X's in this test.
- RTX 2080Ti - 300 seconds - 70 seconds of CPU (R9-3800X) sample size of 3 tasks. Usage unknown - Linux
- GTX 1070 - 1707 seconds - 121 seconds CPU (i7-5820K) sample size of 1 task. Usage 100% - Windows
- R9-280X - 3930 seconds - 730 seconds of CPU (FX8320E) sample size of 2 tasks. Usage 98% - Windows. BOINC wisely did not fire up the 3rd card due to only 16GB of system RAM