I don't know what your material is nor your machine, but you may want to experiment with bit size, depth of cut, cut speed, rapids, Z height and plunge speed. Also a "Z-Level" rough goes quicker than raster, but leaves more waste for the finish bit to cut. Be as aggressive as possible while maintaining an acceptable finish. The "clock" icon will give you an estimate of time to carve, but you need to do some carvings to get that tweaked so it gives a realistic estimate. My machine carved about 10-20% faster than Aspire's guess.