Windows 7: Large file (vhd) sync - not copy

Hi,

As we know vhd files are much larger 50gb+, in case if want to copy such big file to another device / external device weather to back it up or any other reason, as there may be one working vhd and other multiple backup on different external usb or drives, then copying it will take much time. Is there any tool or method to sync both vhd without copying it, like it check for block or byte change between souce and destination vhd so whatever the changes have been done in source vhd can be replicated over destination vhd.

Thanks