Contrary to many blog posts, disabling Prefetch and SuperFetch for SSD drives is actually unnecessary. It IS true that Prefetch and SuperFetch won´t provide a huge advantage for starting applications from SSD drives, as they are fast anyway. ... Prefetch actually should be always stay enabled, even on slower HDDs.
Is it OK to delete prefetch?
The prefetch folder is a subfolder of the Windows system folder. The prefetch folder is self-maintaining, and there's no need to delete it or empty its contents. If you empty the folder, Windows and your programs will take longer to open the next time you turn on your computer.
Is prefetch good for SSD?
Prefetch loads pieces of program files into RAM. By disabling this feature, you free up your system memory. This is one of those tweaks that isn't universal to all SSDs. In fact, it's not recommended if you own an Intel drive, as it purportedly has a negative impact on performance.