Improve the EBS Backup Process Duration

I am having couple of EBS Volumes and I have a cron which I would use to create snapshots from the volumes that are close to 1TB, the entire backup snapshot runs for nearly 5 to 6 hours. I understand that the single biggest factor which effects the delay is due to magnitude of the data changes from the previous backup(delta of data change). To prove that point, the snapshots are much faster if I try to take the snapshot again immediately after a successful backup.

Currently the Volumes are Magnetic, what are the ways to speed up the backup process. Will Changing those to SSD or Provisioned SSD help improve backup running time ?