How can I check the health of my SSD disk
Solution 1:
DiskTester from diglloydTools and its "Recondition" seems like one of the only options.
Solution 2:
there is no one way to diagnose this info because it depends on the controller type used in the SSD. It is possible that the vendor for your controller or the manufactureer of the controller chip have released software, and this is where you should look. What might they tell you? Summary:
an SSD (made with NAND Flash) is composed of "blocks - each one from 4k to 16k usually - that add up to the amount your SSD can hold. Each block can be erased or read from all it once, (although it is possible to write them little bits at a time) but only a certain number of times. It is common to see NAND that has 5,000 to 10,000 times it can be erased. That doesn't sound like a lot (when we are used to talking about gigabytes and gigahertz) but the way in which the SSD writes data to itself - called "wear leveling" - can make this 5k to 10k last a very long time.
The only metric worth measuring becomes how many times each cell has been written to (and which cells are dead altogether, which controllers expect and anticipate), but because each controller is different how to get that number (if possible) and what that number means in terms of percent depleted becomes a highly specific question.
Bottom line, ask your manufacturer for diagnostic tools.