USB C to Thunderbolt connection

Hello all, I have a iMac 27 Late 2013 with Thunderbolt 1 ports and USB 3.0. When I hooked up my new My Passport Ultra for Mac 4TB using the included USB C-USB A connector, I am told it will take 22 hours (probably more to back up my 1.7TB of data. Is there a way to connect my Thunderbolt port (it is the original Thunderbolt, not TB 2 or 3) to the USB C on Passport to improve transfer time? I have tried to figure this out on line but everything seems to be based on TB 2 or 3. Thanks for any help.


At present, Western Digital is not manufacturing external hard drives with thunderbolt port. You can have thunderbolt to USB converter cable from market and test the backup speed in this concern.