USB 3.0 Sandisk Extreme 64GB Slow Speed

My sandisk etreme is slow and not consistent on the speed.

i tried to copy a 2gb file and it finished under 1 minute, then i erased the file, then copied the same file again and this time it finished after 5 minutes. i tried that both on mac and pc, sometimed its fast but most of the time its slow.

any idea if my sandisk extreme is deffective? and what to do with it?

Download usb device tree viewer and make sure your usb is at superspeed and in a 3.o usb port.

any idea if my sandisk extreme is deffective? and what to do with it?

Many things influence speed.  The machine’s hardware, the OS’s work load, the system’s security app/s, the USB drive’s OS configuration Removable vs Performance.  I doubt your drive is defective but it may take you some digging to find out why the speeds vary.

I have jad exactly the same problem - even after a recall and exchange for a newflash drive the response times are abymal on my Acer Switch 10 notebook running Windows 8.1 with USB 3.0 drivers. Paradoxically, on my Sony Vaio (Windows 7 with USB 2.0) it works much better - almost as expected. Conclusion? Forget the security device if using Win 8 on a notebook - not worth the hassel!

Or maybe you can try a different USB port and see if it makes a difference. From what I have experienced as well, the larger the file you’re trying to transfer, the slower it gets since Windows will do some error checking upon file transfer.