I just got my new server with two intel e5-2695 but I was shocked to see that ffmpeg or ubuntu doesn't utilize all cores. top while ffmpeg was running top - 23:35:25 up 2:41, 2 users, load average: 5.35, 4.37, 3.12 Tasks: 333 total, 2 running, 331 sleeping, 0 stopped, 0 zombie %Cpu0 : 0.0 us, 1.0 sy, 35.6 ni, 63.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu1 : 0.0 us, 0.7 sy, 35.5 ni, 63.9 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu2 : 0.0 us, 0.7 sy, 33.4 ni, 65.9 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu3 : 0.0 us, 0.0 sy, 32.7 ni, 67.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu4 : 0.0 us, 0.3 sy, 32.3 ni, 67.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu5 : 0.0 us, 0.3 sy, 33.0 ni, 66.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu6 : 0.0 us, 0.0 sy, 32.6 ni, 67.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu7 : 0.0 us, 0.3 sy, 32.7 ni, 67.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu8 : 0.0 us, 0.7 sy, 32.6 ni, 66.8 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu9 : 0.0 us, 0.3 sy, 33.9 ni, 65.8 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu10 : 0.0 us, 0.0 sy, 35.0 ni, 65.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu11 : 0.0 us, 0.7 sy, 30.0 ni, 69.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu12 : 21.1 us, 0.0 sy, 0.0 ni, 78.9 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu13 : 0.7 us, 0.0 sy, 4.3 ni, 95.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu14 : 0.3 us, 0.0 sy, 5.0 ni, 94.6 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu15 : 24.9 us, 0.0 sy, 0.0 ni, 75.1 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu16 : 0.3 us, 0.0 sy, 3.7 ni, 96.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu17 : 0.7 us, 0.3 sy, 4.9 ni, 94.1 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu18 : 1.0 us, 0.0 sy, 4.6 ni, 94.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu19 : 0.7 us, 0.0 sy, 4.7 ni, 94.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu20 : 11.1 us, 0.0 sy, 0.0 ni, 88.9 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu21 : 1.3 us, 0.0 sy, 4.6 ni, 94.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu22 : 2.0 us, 0.3 sy, 4.3 ni, 93.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu23 : 96.7 us, 1.0 sy, 0.0 ni, 2.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu24 : 0.0 us, 0.0 sy, 0.7 ni, 99.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu25 : 0.0 us, 0.0 sy, 3.0 ni, 97.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu26 : 0.0 us, 0.0 sy, 1.3 ni, 98.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu27 : 0.0 us, 0.0 sy, 4.0 ni, 96.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu28 : 0.0 us, 0.0 sy, 1.7 ni, 98.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu29 : 0.0 us, 0.0 sy, 1.7 ni, 98.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu30 : 0.0 us, 0.0 sy, 1.7 ni, 98.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu31 : 0.0 us, 0.0 sy, 1.0 ni, 99.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu32 : 0.0 us, 0.0 sy, 0.7 ni, 99.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu33 : 0.0 us, 0.0 sy, 1.7 ni, 98.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu34 : 0.0 us, 0.0 sy, 2.0 ni, 98.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu35 : 0.0 us, 0.0 sy, 1.0 ni, 99.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu36 : 0.0 us, 0.0 sy, 0.0 ni,100.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st ffmpeg was sent with -threads 0 *I also tried sending ffmoeg with -threads 500- no difference