Modern computers often have processors that contain more than one core. Each core can work in parallel to handle computationally intensive tasks. To improve the performance of PTLens on your system choose Tools > Options (PC) or Preferences (Mac) and specify the number of threads on your system. The following table illustrates the time it takes to process a 24MP (6000 x 4000 pixel) image on a system with a processor that has 4 cores and supports, via hyperthreading, 8 threads. The image was corrected for barrel-pincushion distortion and all sliders for Perspective, Vignetting, and Chromatic Aberration were enabled.