Very sluggish hard drive
 

My hard drive was recently replaced on my 2014 iMac. I used a backup drive created by SuperDuper to recreate my hard drive. My iMac is very sluggish after doing this. Any suggestions to eliminate this behavior would be appreciated. I'm running System 10.11.1 (el capitan). Thanks

Initial boot (and a while after) will be slower as various caches, indices and the like are recreated. Give it some time and things will get faster again (assuming the replaced drive is fast).