[Lcms-user] Multi-threading Little CMS Performance on Modern High-End Hardware

[Noel C. <NCa...@Pr...>]

Hi Marti and Little CMS list members,

I've been exercising Little CMS on a new AMD Threadripper Pro system.  This machine has the AMD Ryzen Threadripper Pro 5975X processor with 32 cores (64 logical processors in Windows with SMT enabled).  My software divides up the color management processing into multiple threads depending on several factors including image size, cache sizes, etc.  I thought you might like to see some representative performance numbers from Little CMS doing RGB to RGB color transforms (from image to monitor profiles)...  Note that I am NOT using the Little CMS plug-ins, just the base code, compiled for Windows using Visual Studio 2022.

Performance Message: Total Time =  10.617 milliseconds, ConvertColorOf() - Completed color conversion using 63 simultaneous threads.  Image:  3032 x 2016 pixels x 16 bits per color.

Performance Message: Total Time =  15.247 milliseconds, ConvertColorOf() - Completed color conversion using 64 simultaneous threads.  Image:  3852 x 2598 pixels x 8 bits per color.

Performance Message: Total Time =  18.508 milliseconds, ConvertColorOf() - Completed color conversion using 64 simultaneous threads.  Image:  4246 x 3925 pixels x 16 bits per color.

Performance Message: Total Time =  50.934 milliseconds, ConvertColorOf() - Completed color conversion using 64 simultaneous threads.  Image:  8492 x 7850 pixels x 8 bits per color.

Performance Message: Total Time =  40.886 milliseconds, ConvertColorOf() - Completed color conversion using 64 simultaneous threads.  Image:  8492 x 7850 pixels x 16 bits per color.

Performance Message: Total Time = 241.950 milliseconds, ConvertColorOf() - Completed color conversion using 64 simultaneous threads.  Image:  8492 x 7850 pixels x 32 bits per color.

Extrapolating from the next to last 66 megapixel entry above, we're seeing more than 1.6 gigapixels per second color-transformed.

-Noel Carboni
 ProDigital Software