Samsung 840 EVO SSD 250 GB won't boot using SATA_6G-12 connectors AHCI mode on P7P55D-E PRO MB. The drive is recognized but won't boot. OS is WIN 7 64 bit. This HD boots OK and is fast on SATA 1-6 connectors in IDE mode. BIOS is V 1502 11/04/2010.
Do you install the Marvell 9123/9120 sata controller driver? Because you connect the SSD into it. http://www.asus.com/Motherboards/P7P55DE_PRO/#support