If you want to have really fast disk and have enough RAM (f.e. I have 32Gb) you can create so called “RAM disk”:
diskutil erasevolume HFS+ RAMDisk1 $(hdiutil attach -nomount ram://41943040)
This will create 20Gb drive (10240*2048=41943040)
When you finish working gust unmount drive in Finder or Terminal ;)