Legacy ImageMagick Discussions Archive

Hi,
in latest version ImageMagick-6.8.9-8, i compile with opencl and test resize(convert src.jpg -filter box -resize 248x248 -bench 30 logo.jpg)
but the performance of using opencl is slower than only use cpu openmp.
I use cuda6.5

>convert src.jpg -filter box -resize 248x248 -bench 30 logo.jpg

openmp
Performance[1]: 30i 78.947ips 1.000e 0.370u 0:00.380
Performance[2]: 30i 81.081ips 0.507e 0.380u 0:00.370
Performance[3]: 30i 73.171ips 0.481e 0.390u 0:00.410
Performance[4]: 30i 78.947ips 0.500e 0.380u 0:00.380
Performance[5]: 30i 75.000ips 0.487e 0.390u 0:00.400
Performance[6]: 30i 73.171ips 0.481e 0.400u 0:00.410
Performance[7]: 30i 81.081ips 0.507e 0.380u 0:00.370
Performance[8]: 30i 75.000ips 0.487e 0.370u 0:00.400

openmp + opencl
Performance[1]: 30i 7.143ips 1.000e 13.570u 0:04.200
Performance[2]: 30i 17.143ips 0.706e 1.750u 0:01.750
Performance[3]: 30i 17.045ips 0.705e 1.770u 0:01.760
Performance[4]: 30i 17.143ips 0.706e 1.750u 0:01.750
Performance[5]: 30i 17.045ips 0.705e 1.750u 0:01.760
Performance[6]: 30i 17.045ips 0.705e 1.760u 0:01.760
Performance[7]: 30i 17.143ips 0.706e 1.750u 0:01.750
Performance[8]: 30i 17.143ips 0.706e 1.750u 0:01.750

if anybody had meet the same thing.

Download http://www.imagemagick.org/download/bet ... -9.tar.bz2. Let us know if the OpenCL performance is restored. Thanks.

Hi, I had test version ImageMagick-6.8.9-9
>convert src.jpg -filter box -resize 248x248 -bench 30 logo.jpg

openmp:

Performance[1]: 30i 115.385ips 1.000e 0.370u 0:00.260
Performance[2]: 30i 120.000ips 0.510e 0.360u 0:00.250
Performance[3]: 30i 115.385ips 0.500e 0.370u 0:00.260
Performance[4]: 30i 78.947ips 0.406e 0.370u 0:00.380
Performance[5]: 30i 120.000ips 0.510e 0.360u 0:00.250
Performance[6]: 30i 120.000ips 0.510e 0.370u 0:00.250
Performance[7]: 30i 120.000ips 0.510e 0.360u 0:00.250
Performance[8]: 30i 120.000ips 0.510e 0.360u 0:00.250


openmp + opencl:

Performance[1]: 30i 14.218ips 1.000e 1.910u 0:02.110
Performance[2]: 30i 16.760ips 0.541e 1.800u 0:01.790
Performance[3]: 30i 16.949ips 0.544e 1.770u 0:01.770
Performance[4]: 30i 16.949ips 0.544e 1.780u 0:01.770
Performance[5]: 30i 16.949ips 0.544e 1.760u 0:01.770
Performance[6]: 30i 16.854ips 0.542e 1.780u 0:01.780
Performance[7]: 30i 16.949ips 0.544e 1.760u 0:01.770
Performance[8]: 30i 16.949ips 0.544e 1.780u 0:01.770

using opencl is also slower than only openmp.

By the way, has anybody knowns wether need some special configuration that make opencl speed up works, or post your benchmark about using opencl

As I understand it, OpenCL has a non-negligible overhead. So for small image, it may be slower than without due to the overhead. I do not know what size your input image is.

fmw42 wrote:As I understand it, OpenCL has a non-negligible overhead. So for small image, it may be slower than without due to the overhead. I do not know what size your input image is.

My src.jpg size is 549 * 412 about 59kb.