Apple AirPort Time Capsule very slow backup
I am doing a backup on my 3TB Time Capsule and running High Sierra. The Time Machine window says there are 35GB to back up, and it is estimating over 24 hours. Is this normal, it seems very slow for just transferring data from my iMac to an external drive?
iMac (27-inch, Late 2013), OS X Mavericks (10.9.2)