TRIM support is essential for write operations to a SSD. It about doubles the speed with which write operations are being executed. However, at this time it is only useful with Windows 7 because that is the only operating system that supports TRIM - and both the drive's controller and the operating system have to cooperate to make TRIM operate.
If you are not certain whether your SSD controller supports TRIM, there is an easy way to find out.
Open an elevated Command Prompt (run as admin) and paste this command into the Command Prompt window:
fsutil behavior query DisableDeleteNotify
If Command Prompt returns a 0 (zero), your drive supports TRIM and it is enabled.
If it returns 1 (one), the file system has disabled TRIM for your drive. This means your drive's controller does not support TRIM.