The VX700 DDR2 interface can support speeds up to 266 MHz. This paper highlights a typical design approach that can be adopted for an embedded PC (X86 based) board memory subsystem using a VIA VX700 ...
This is because the pin configuration for a DDR3 RAM is different from that of DDR2 or DDR4, this is why you need to make sure that the RAM you buy must be compatible with your computer.