I do daily full back up of a 150G bytes database to a local drive of its server and it took 2 hours and 45 mins. This database is on SQL 2008 standard sp3 server say server A. I have the exact same database on a different SQL server machine say server B and it took 10 mins. The only difference is server B has SQL 2008 r2 standard sp1. However, I also have a SQL 2008 standard sp3 machine say server C, which is backing up a 240 Gbytes db in 20 mins. The backup job occurred at 2:00 am on server A which should be a quiet time and I checked if there are any jobs and windows scheduled tasks running during the back up on server A and I found none. I ran a test backup on server A and found IO and cpu are not being overwhelmed. In fact, the performace encounters (average read/write queue IO) are within the threadholds. What could be wrong with the backup on server A? Any thoughts on this are very much appreciated.