They take about 3.5 seconds per test with moltenvk, 80 ms with Metal. They shouldn't be that much slower. This makes running the tests take like 10 minutes which is too long.

This may be indicative of some inefficiency in the vulkan renderer, but probably is just an artifact of the golden executable.

reproduction

Execute impeller_golden_tests --working_dir=<PATH> --gtest_filter="*Vulkan"