Table 2 Pipeline times (ms) and theoretical speedups
From: Parallelization of the optical flow computation in sequences from moving cameras
Nodes | Distribution | ms per 502 × 288 image | ms per 720 × 576 image |
|---|---|---|---|
16 | 4 nodes execute the _smooth | ||
and _derivatives tasks | T = max(12,8,7,7 + 3) = 12 | T = max(40,30,25,25 + 10) = 40 | |
12 nodes execute the | |||
velocities and | T = 137/12 = 12 | T = 395/12 = 33 | |
out_velocities tasks | Timg = max(12,12) = 12 ms | Timg = max(40,33) = 40 ms | |
Max speedup = 174/12 = 14.5 | Max speedup = 525/40 = 13.1 | ||
8 | 1 node executes the | ||
T_smooth and X_smooth tasks | T = 12 + 8 = 20 | T = 40 + 30 = 70 | |
1 node executes the Y_smooth | |||
and _derivatives tasks | T = 7 + 7 + 3 = 17 | T = 25 + 25 + 10 = 60 | |
6 nodes execute the | |||
velocities and | T = 137/6 = 23 | T = 395/6 = 66 | |
out_velocities tasks | Timg = max(20,17,23) = 23 ms | Timg = max(70,60,66) = 70 ms | |
Max speedup = 174/23 = 7.6 | Max speedup = 525/70 = 7.5 | ||
4 | 1 node executes every | ||
task except velocities | T = 12 + 8 + 7 + 7 + 3 = 37 | T = 40 + 30 + 25 + 25 + 10 = 130 | |
3 nodes execute the | |||
velocities and | T = 137/3 = 46 | T = 395/3 = 132 | |
out_velocities tasks | Timg = max(37,46) = 46 ms | Timg = max(130,132) = 132 ms | |
Max speedup = 174/46 = 3.8 | Max speedup = 525/132 = 4 |