How can I tell if my Mac CPU supports AVX?
Execute this command in Terminal:

sysctl -a | grep machdep.cpu.features


You'll get a report out like this:


  Redacted-Family-iMac:~ redacted_user$ sysctl -a | grep machdep.cpu.features
  
  machdep.cpu.features: FPU VME DE PSE TSC MSR PAE MCE CX8 APIC SEP MTRR PGE MCA CMOV PAT PSE36 CLFSH DS ACPI MMX FXSR SSE SSE2 SS HTT TM PBE SSE3 PCLMULQDQ DTES64 MON DSCPL VMX SMX EST TM2 SSSE3 CX16 TPR PDCM SSE4.1 SSE4.2 x2APIC POPCNT AES PCID XSAVE OSXSAVE TSCTMR AVX1.0 RDRAND F16C


I've bolded the presence of the AXV1.0 CPU feature in the report from my Mac: iMac 27" Late 2012 3.4GHz Core i7.

(Answer lifted from this site.)