How much does the CPU affect your HDD speed, if at all?

[Legolas8181]

I have a 5,400RPM SATA II HDD in my laptop and if I was trying to back some contents from there onto my external 3TB SATA III 7,200RPM drive while trying to listen to music on the SATA II drive, how much would the CPU be affecting that or is that all down to the HDD?

 

[ewok93]

It does not affect it at all.

 

[hunter315]

Your CPU isn't impacting the speed, using the same drive for two tasks does greatly impact the speed though. Your hard drive had to flip back and forth between what it was loading so it could play it and what it was loading onto the external drive. Your CPU does a very minimal amount of processing when transfering files, the speed of that operation is almost entirely dominated by the hard drive's capabilities and since HDDs are spinning disks they are much better at reading data sequentially and continuously and when you hop between tasks it has a couple milliseconds of travel time between the two tracks which significantly reduces the average speed.