Hi
If your laptop has only one drive (which is common), then SSD is preferred. Recording to an HDD is only practical when it is dedicated solely for recording (does not contain OS files etc).
Regarding USB. If your laptop is based on Intel chipset of 7x/8x series, then it should support 4 PS Eyes at 60 fps, and possibly 6 PS Eyes at 40-50 fps. If you have a second laptop, you can use the distributed recording feature to record with many cameras.
Regarding processing speed. See estimated performance chart on our web site:
http://ipisoft.com/pr/GPU_speed_v_14_04.pdfIt does not contain 740M though. However, its performance should fall in range between 640M and 750M (which are listed), I believe closer to 640M.