gpu vs. cpu computations Árni einarsson jacek kolodziej

GPU vs. CPU computations

Árni Einarsson

Jacek Kolodziej

3x3 image filters

• Edge detectionComputations only

Laplace operation : Frames per second

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 200 400 600 800 1000 1200

Resolution

FP

S

GPU 4 nb GPU 8 nb CPU 4 nb CPU 8 nb

3x3 image filters

• Edge detectionComputations only

Laplace operation : High resolution FPS

0

100

200

300

400

500

600

700

0 200 400 600 800 1000 1200

Resolution

FPS

GPU 4 nb GPU 8 nb CPU 4 nb CPU 8 nb

3x3 image filters

• Edge detection Computations only

Laplace operation : Pixels per second

0

5.000.000

10.000.000

15.000.000

20.000.000

25.000.000

30.000.000

35.000.000

40.000.000

45.000.000

50.000.000

0 200 400 600 800 1000 1200

Resolution

PP

S

GPU 4 nb GPU 8 nb CPU 4 nb CPU 8 nb

3x3 image filters

• More computation than lookups

7751,94

2283,11

584,80151,22 39,1442,06 10,43 2,55 0,64 0,16

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

64 128 256 512 1024

Resolution

FP

S

GPU GPU

3x3 image filters

151,22

39,1442,06

10,432,55 0,64 0,16

0

20

40

60

80

100

120

140

160

180

200

64 128 256 512 1024

Resolution

FP

S

GPU GPU

Edge detection

• CPU computation time depends on input data, can be up to 100x slower (!)

Possible reasons:– CPU jump predictions (?)– Cache management (?)– Dependant on input data in multiplication (?)– … (put your ideas here)

Water surface simulation

• Computations only performance

Water splash: computations only

8.871,3

1.979,5

348,870,7 16,6

3.422,5

157,5

2.040,9

587,9

40,0

0,0

1.000,0

2.000,0

3.000,0

4.000,0

5.000,0

6.000,0

7.000,0

8.000,0

9.000,0

10.000,0

64 128 256 512 1024

grid size

FP

S CPU FPS

gpu FPS

Water surface simulation

• Computations & visualization (with synchronization)

Water splash: computations & visualization (with vertical synchronization, 60Hz)

59,8 59,8 59,8

16,8

3,3

59,8 59,8 59,8 59,8

29,4

0,0

10,0

20,0

30,0

40,0

50,0

60,0

70,0

64 128 256 512 1024

grid size

FP

S CPU FPS

gpu FPS

Water surface simulation

• Computations & visualization (without synchronization)

Water splash: computations & visualization(without vertical synchronization)

561,3 550,9

232,5

17,3 3,4

337,3303,7

174,9

81,9

31,9

0,0

100,0

200,0

300,0

400,0

500,0

600,0

64 128 256 512 1024

grid size

FP

S CPU FPS

gpu FPS

Questions ?