As long as the laptop uses an SATA hard drive, you'd be fine to use an SSD. Some drives have their own garbage collection built-in, so TRIM wouldn't be a necessity...and neither is AHCI. It will work fine in IDE mode. Your speeds will be somewhat limited, if the laptop only has SATA2 ports, but it will still be much faster than an HDD, and will help with heat and battery life as well.