How do I check the health of my Samsung SSD?

I've got a Samsung SSD on Windows that's giving CHKDSK errors. How do I check the health?

Samsung Magician Software

From Samsung SSD Downloads:

The Samsung Magician SSD management utility is designed to work with all Samsung SSD products, including 470 Series, 830 Series, 840 Series and 850 PRO SSDs. This software is not compatible with other manufacturer's SSDs.

From the Samsung Magician Introduction and Installation Guide:

The Samsung Magician software is designed to help users easily manage the health and performance of their Samsung SSD. In addition to providing vital SSD health status information, Magician will assist users in updating firmware, measuring performance, and optimizing the configuration of a Windows operating system installation.

Samsung Magician software from the Samsung SSD Downloads website. The latest version of Magician software is recommended for optimal performance.

The latest version of the Samsung Magician Introduction and Installation Guide can be downloaded from here. Samsung frequently updates the Samsung Magician Introduction and Installation Guide, so if the link doesn't work anymore, you can also find the Samsung Magician Introduction and Installation Guide by googling it.