Hello... the PCIe Slot version on that MB is 1.0... this could be a problem with compatibility... can you test with a borrowed card first?
https://www.asus.com/us/Motherboards/P5GCMX1333/specifications/ https://en.wikipedia.org/wiki/List_of_Intel_chipsets
Hello... the PCIe Slot version on that MB is 1.0... this could be a problem with compatibility... can you test with a borrowed card first?
https://www.asus.com/us/Motherboards/P5GCMX1333/specifications/ https://en.wikipedia.org/wiki/List_of_Intel_chipsets