flac
Intel Core i5-7200U testing with a Dell 0G35R8 (1.23.3 BIOS) and Intel HD 620 3GB on Debian 9.7 via the Phoronix Test Suite.
HTML result view exported from: https://openbenchmarking.org/result/1902117-SP-FLAC4291499.
FLAC Audio Encoding
WAV To FLAC
Phoronix Test Suite v10.8.4