As far as I know I know motherboard doesn't even have a Marvell controller and I heard they are extremely bad.
Regarding the drivers, when I check on the ASUS website I find 2 different entries under SATA.
ASUS - Motherboards- ASUS Rampage IV Extreme
It shows Asmedia AHCI Driver V1.3.4.0 for Windows 8 32bit & 64bit.(WHQL), from what I can tell the only newer one is 1.3.8.0 however I cannot find anything official from Asmedia themselves.
And
Intel(R) Rapid Storage Technology enterprise Driver Software V3.5.0.1092 for Windows Vista/7 32bit & 64bit.(WHQL)
Intel(R) Rapid Storage Technology enterprise Driver Software V3.5.0.1096 for Windows 8 32bit & 64bit.(WHQL)
Intel(R) AHCI/RAID Driver for Windows Vista/7/8 32bit & 64bit.
I have used the Intel Rapid Storage Technology Enterprise Driver before but only from ASUS, if I try to download it from Intel the installation tells me that my hardware does not support it. The second one, the Intel AHCI/RAID Driver I can't even find on the Intel website so I am using whatever version windows has found.
From what I know my computer has experienced freezing with both drivers and ONLY with Windows 8. I could check to see if my SSD drives have a loose connection anywhere or maybe I could try a different port, but I have no idea if that would help.
EDIT: I have checked the manual and my SSDs are connected to the Intel X79 Serial ATA 6GB/s connectors. Nothing is connected to the Asmedia ones.