I was intending on installing Windows 7 on my baseline macbook pro with retina display (256gb SSD). What would be a good drive partition size for windows? I'm mostly concerned with speed, I want enough space on the windows partition to run games off a USB 3 hard drive smoothly, but not so much that it will affect the performance of the OSX partition. In addition, will gaming from a USB 3 hard drive be practical? I did some research and it seems to be, but I wanted to be sure.