MapTiler is a multi-threaded program. The modern CPUs has multiple cores and support of Hyperthreading which provides multiple logical CPUs per core. This way MapTiler can provide higher performance even on a dual-core computer.
The Free version is limited to 1 CPU, MapTiler Start and Plus have a limit of 2 CPUs for rendering, which doubles the rendering speed.
The Pro version is able to render on 4 or more CPUs depending on your license. With such power, it is easily able to render extremely large datasets (e.g. continents or the whole world).
The number of purchased CPUs is automatically detected and if the computer is capable of faster rendering, it is possible to purchase additional CPUs for higher rendering speed. The information about the number of CPUs and possible upgrade is available in File -> License… or it is visible during rendering.
Apart from buying more CPUs, you can also reach the speed gain by optimizing your workflow, especially for a large amount of data. MapTiler is most effective reading 256x256 blocks of data.
If the source data are correctly prepared (tiled in 256x256 blocks in GeoTiff, ECW, JPEG2000 format), then rendering is very fast. Otherwise, MapTiler is able to process such files, but it takes longer time.