You will not get those speeds even on high end drives dude.

500 megabits per second (Mbit/s) equates to 62.5 Mb/s) megabytes per second and USB 2.0 (theoretically) tops out at 480 Mbit/s (60 MB/s). So if 62.5 Mb/s is required, USB 2.0 operating at its highest theoretical bandwidth will still not be enough. No drive connected with USB 2.0 can meet your needs and there are plenty of variables that will prevent your drive from reaching its maximum theoretical bandwidth.

SSDs have sequential read speeds of many times greater than the 62.5 Mb/s you say you require and mechanical hard drives can easily reach this transfer speed. I can help, but can you tell me what it is you're trying to accomplish here? Do you need a drive that can write data quickly enough for some task like video recording? Does it absolutely have to be external? What ports does your computer have?