Hello A.Scott.A, thanks for contacting us through the Intel Communities.
About your question, I found this driver that might help you to get AHCI support on your system however I cannot guarantee you it is going to work. https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=15551&ProdId=2101&lang=eng&OSVersion=%0A%09%09%09%09%09%09%09%09%0A%09%09%09%09%09%09%09&DownloadType=
You would need to download the .ZIP file and a floppy drive will be needed.
There is additional information at the following links
Thanks for replying. I've tried to install this driver, but it says "Required hardware could not be found". It seems the oldest supported controller is "Intel(R) 82801ER I/O Controller Hub (ICH5R)". In my machines there is - Intel(R) 82801EB controller.
It is funny that there are 2 S-ATA slots on this motherboard, so theoretically it should support SSD drives in AHCI mode natively. Also in BIOS there is AHCI option, but it doesn't make any difference when I set it on. The PC manufacturer (IBM/Lenovo) did not provide any drivers for this mode.
Well, it seems my SSD drive will be working in legacy mode then