Android 4.3 uses TRIM to keep SSDs efficient
It is not a big secret: Every operating system will slow down after a certain amount of time unless it is being constantly serviced and optimized. Who among us has never in the past started up the good old defragmentation command under Windows and then gone for a coffee or five, depending on the size of the HDD?
Android has a similar problem with SSD storage. Let's take a look at the Nexus 7: When using the old model (before being updated to Android 4.3), you can actually witness a decrease in performance after several weeks or months—depending on how actively you use your local storage. Lots of writing and deleting data on the solid state drive will inevitably slow your system down. But why? Well, the problem is—as so often in life—communication, or the lack thereof. When data is deleted from the SSD, the controller handles that part of the drive as if it still had valid data. This empty space can be used for internal optimization, but the controller simply does not know any better. Yes, you could go ahead and root your Nexus 7 and then use some tools like LagFix to fight this problem. Such a procedure takes time and to be blunt: How many users even are aware of it, let alone know how to do it?
With Android 4.3 this problem should be a relic of the past, according to Anandtech. The new Android version has a TRIM command called fstrim, which executes on a daily basis is the tablet is idle for more than an hour and has either more than 80% of battery life or is attached to a charger. This command tells the eMMC (embedded Multi-Media Controller) which areas of the SSD are free to use for internal processes and optimization. Going back to our Windows reference from above: Windows 7 is the first Microsoft OS with this little life saver.
The term life saver might be an exaggeration, but then again, maybe not: Not only will using TRIM hold access speed at a consistently high rate, it will also enhance your SSD's life by minimizing access and wear.