CrystalDiskMark

I only use this for testing read and write speeds of hard drives. It's wonderfully easy to use, with an intuitive interface, and free! BUT, while it works great for SSDs, if you have a mechanical hard drive, you can only use it on a fresh drive with almost nothing written to it. Otherwise, the numbers you get are meaningless. This is because when the drive is empty, CrystalDiskMark reads and writes from the first empty sectors, which are the outermost sectors, which are the fastest sectors. But if the drive isn't empty, it reads and writes from somewhere else--probably the first block of free sectors. For instance, I have an Ultrastar that I tested a week ago when it was empty, and CrystalDiskMark said it read at 260 MB/s. Today it's almost entirely full, and CrystalDiskMark says it reads at 147 MB/s. I've had the same experience with other UltraStar drives, every one of which reads and writes at 256-261 MB/s when it's empty, and much slower when it isn't.

Very good tool!

This is a great handy utility. Stable and easy to use.

Siempre funciona muy bien. :)

Very good.