Solved SSD but no AHCI, how much do I need to worry about TRIM?

I recently picked up a used Dell 620s cheap to replace a workstation I built over 10 years ago, and tide me over until I save up enough to build a more robust machine. I figured I could give it a boost with an SSD for the boot drive, which I could then migrate to the new machine too. The BIOS has no options for AHCI so I understand that the drive will be handled in an IDE mode. The functionality that I am missing by AHCI does not concern me, except for the references to TRIM. So the BIOS does not support passing the TRIM function, but some things I have read suggest that the Samsung Magician software is able to do it? It appears that Windows 8 will recognize the drive as an SSD, is it smart enough to send TRIM to the SSD occasionally too? Or do I use the Samsung software periodically to refresh the SSD?. Or is the SSD on its own to handle garbage collection in my system, causing it to wear out prematurely?

Installing the Samsung 840 EVO 120 GB tonight (and reinstalling Win 8 on it) so I will update this with anything I notice in the process...

After Windows Installation, you can try if you can enable trim this way. You can open the Admin Command prompt and type:
fsutil behavior query DisableDeleteNotify

DisableDeleteNotify = 0 : TRIM is already enabled and working in Windows
DisableDeleteNotify = 1 : TRIM is not enabled

To enable SSD TRIM support in Windows
fsutil behavior set DisableDeleteNotify 0