Due to energy saving settings many hard drives will spin down when they are not in use or are inactive. Every time you’ll access the hard drive it will spin up again. However spin up and spin down of a traditional hard drive will, in general, decrease its life. Therefore we normally prefer not excessive spin ups or spin downs with a hard drive. The optimum is to keep the hard drive spinning when it is operating. Also, accessing your hard drive will take much longer if the hard drive have to spin up every time when you want to access a file. The performance will be decreased a lot. The generated noise by spinning up will also occur less.
Prevent hard drive from spinning up and down
You want to prevent the HDD from spinning up and down to have the best performance and to keep it in best shape. You can prevent this by creating a task to allow it spinning and run it in the background. However there is also a program which allow you to control this, named CrystalDiskInfo. You can download the standard edition from their website. Change the spin feature by going to function > advance feature > AAM/APM control. Select the hard drive and change the settings for APM (by APM section between Min. Power and Performance.