I recently upgraded my Sony Vaio E series laptop from Windows 8.1 to Windows 10. The upgrade went smooth, but Windows 10 was constantly causing disk activity, there by reducing the performance of the laptop.
On investigation it turned out that the Vaio utilities like Vaio Care etc.. were not working correctly on Windows 10 and were constantly accessing the disk. I uninstalled Vaio Care and then the performance issue was gone, the laptop started running smoothly again, the way it ran under Windows 8.1.
I eventually ended up resetting the laptop and restoring it to plain Windows 10. This gives the best performance on my Vaio.