Hi, I've tried performance testing with UI tests in Xcode 11 and I came to the same conclusion regarding XCTCPUMetric and XCTMemoryMetric... Useless. The data collected does not make sense or I also see a lot of "0" in the values recorded. I can't read anything about it online, no bug reports or complains on SO. I'm glad someone else is experiencing the same issue. However since Xcode 12, I can't see the test report popup and can't set the baseline for XCTStorageMetric, XCTCPUMetric or XCTMemoryMetric. The performance tests just always pass. Have you experienced something similar? It would be great if someone from the XCTest team could respond.