This product is really good. I bought it before 6 months. This one is working great. The storage capacity of this hard disk is 931gb, which is good. About transfer speed, if plugged in into usb 3.0, it gives around 70-90mbps reading speed and 40-50mbps writing speed. With usb 2.0, it gives 30 to 40mbps reading speed and 20-30mbps writing speed. I filled half of mine. Again one thing about speed, it depends on file type, means, wheather it is a video file or a document file or any software file. Overall a perfect buy.