Motherboard series asus x299 form factor atx supports multi core processors 18 core compatible cpus intel core i5x intel core i7x intel core i9x processor codenames kaby lake x skylake x chipset intel x299 memory slot 8 ram operation mode quad channel ram type ddr4 memory clock speed 2 667 mhz memory clock speed oc max 4 133 mhz specification pc4 21336 specification oc max pc4 33064 maximum memory expansion 128 gb pcie 30 number of pci x x