I purchased this 512 GB SSD to replace an aging 250 GB Western Digital hard drive in an old laptop. The laptop took two minutes to boot up and get logged in to the point where it was usable. Once I replaced the mechanical drive with this SSD, from power up to log in to having the laptop in a usable state can be done within 15 seconds. The laptop might be old but it was well worth the small investment to extend its life. The only drawback of this SSD brand is that they do not supply any cloning software to do a clean full transfer from the old hard drive to the SSD, so plan on purchasing some system cloning software if you're going to do what I did.