Most efficient transfer protocol to Nexus Switch?

Hi all,

New here, apologies if I break any rules...

I'm just wondering what people use to transfer files to remote Nexus switches? I'm currently using TFTP from a jumpbox but I'm getting speeds of ~200kbps, and with the 300MB+ images on the Nexus this is taking hours to transfer. Wondering if anyone knew of any better ways of remotely loading images to the switches? I've tried SCP in the past but I remember that being a similar speed.

Thanks!

Steve