SMP

Source video 1

The video is a 95 minutes 720x480 16/9 NTSC dvd movie. The raw mpeg2 video stream and the ac3 audio stream is 3699878452 bytes long. The computer has two cpu with hyperthreading.

-encode
-cpu
hyperthreading
kernel
size (bytes)
job time PSNR
3:2:1
1
off
2.4
2869812542
1h16m
46.60
3:2:1
2
off
2.4 2871568120
0h56m
46.60
3:2:1
4
on
2.4 2874968680
0h54m
46.62
3:2:1
1
off
2.6 2869812542
1h19m
46.60
3:2:1
2
off
2.6 2871568418
0h56m
46.66
3:2:1
4
on
2.6 2874967188
0h52m
46.80

with 0 B frames
-encode
-cpu
hyperthreading
kernel
size (bytes)
job time PSNR
3:3:2
1
off
2.4
2323792246
4h41m
45.61
3:3:2
2
off
2.4 2324400752
3h01m
45.61
3:3:2
4
on
2.4 2342798810
3h04m
45.62
3:3:2
1
off
2.6 2323792246
4h37m
45.61
3:3:2
2
off
2.6 2324341826
2h53m
45.61
3:3:2
4
on
2.6 2326579764
2h39m
45.67

with 2 B frames
-encode
-cpu
hyperthreading
kernel
size (bytes)
job time PSNR
3:3:2
1
off
2.4
1669502912
6h18m
44.54
3:3:2
2
off
2.4 1695440922
9h16m
44.50
3:3:2
4
on
2.4 1721917064
13h36m
44.51



-encode
-cpu
hyperthreading
kernel
size (bytes)
job time PSNR
3:4:2
1
off
2.6
2975708584
12h21m
47.57
3:4:2
2
off
2.6 2998988364
7h10m
47.55
3:4:2
4
on
2.6 3038059572
6h10m
47.55


Comments

If you have more than 1 physical cpu, you have a gain in speed of about 25-40%. If you are using B frames, always use -cpu 1. If your cpu has hyperthreading, use kernel 2.6.x.