SOLID-STATE DRIVE TOOLBOX
If you want more control over the 535 Series you will need to download the latest version of the SSD Toolbox. Once you launch it the main screen will inform you of the remaining capacity on the drive and the drive health and remaining life (you can also access SMART info from here).
You can enable the TRIM command of the drive manually (Intel recommends doing so once a week) via the optimizer tab.
Intel has also placed two diagnostics in this software so i do suggest running both at least once a month especially if you plan on storing critical data on the drive.
The secure erase feature can be extremely useful in case you decide to sell the drive or transfer it onto another system.
Instead of searching online for a new firmware you will need to search for new versions of the SSD toolbox since it's contained inside.
Finally the system tuner lets you finetune some system services which are not ment for use with SSDs.