I have installed Ubuntu 12.04 on a 55GB Adata S599 SSD. I have a Asus M4N68T motherboard that does not support AHCI. Bootup takes a lot longer than expected and working in the system is not even close to an option. Is this an AHCI issue or is there something else I can try and do?
Unfortunately AHCI is needed. You need to make sure your SATA controller is set to AHCI mode (you can do so in your BIOS). AHCI is needed for TRIM support, and to get the maximum performance out of an SSD.
TRIM support does help maintain the highest performance of an SSD. It’s recommended to run your SSD in AHCI mode to enable TRIM to do its job.
Please read up about what AHCI is before claiming that AHCI is not supported by your motherboard:
Infact every motherboard that comes with SATA connectors supports AHCI. I looked up the manual for your motherboard, there may not be an option for choosing the AHCI operation mode. Which is perfectly fine, it just means that SATA drives can not be switched into Parallel ATA emulation mode.
There are a few BIOS Updates available:
I would suggest updating the BIOS to the latest available firmware, if that does not help buy a new motherboard.