SanDisk Extreme 500 (480GB) - Speed Issues

no software. this is a normal MSC device so the drivers should be native to you OS. You could check to see if there are updated USB chipset drivers from the laptop manufacturers website. What kind of laptop do you have and does it have USB 3.1 ports? Do you have any other USb 3.0 devices that are performing correctly? Also how are you measuring the speed? A benchmark is most helpful. Use Crystal Disk Mark to benchmark the device.