Question : Problem: Backups to esata drive slow

I am backing up aprox 240 gig of data to an ESATA drive on a nightly basisusing Windows ntbackup. I was using a USB drive and the backups took 12 - 14 hrs. The tests I did with the ESATA drive on 15 - 20 gig was 4 - 6 times faster than USB which was expected. The backups with the ESATA drives at 240 gig take about 10 - 12 hrs. 4 - 6 hrs is what I expected. Any ideas on how to speed up the backups or what might be wrong? The backups need to be completed in under 8 hrs. Would 3rd party software help? Any ideas would be appreciated.

Answer : Problem: Backups to esata drive slow

What are you backing up (type of data, many small files etc)? What else is running on that server? What are the hardware specs of the server? Have you turned off realtime and on access virus scanning during the backup? Are any other jobs running while backing up?