I would like to suggest the use of graphics board GPUs to render images.
The jpg files from my camera run between 8 and 17 meg. Each jpeg takes between 4 and 5 seconds to render. I had to scale jpeg size down to 1/4 size to get an acceptable rendering time. I could wait that long for one picture, but when viewing a slide show, that wait is seemingly interminable. My graphics board contains GPUs that supports massive parallel processing capability which is used by many image processing software programs. Photoshop, Paintshop Pro and PowerDirector are three that I use that take advantage of the graphics board GPU.