I am running XP Pro 32-bit. I want to replace the Video Card. Nothing great or expensive...just a decent one."}
Due to the different pin design of DDR2 and DDR3, it will be physically impossible to put a DDR2 stick into a DDR3 slot. You will need to have DDR3 RAM. When you buy it, be sure that it runs at 1.65V or less; that's RAM designed for the X58 and P55 chipsets. There are some motherboards offering the option of both DDR3 and DDR 4 memory slots, but you get half as many as you would on a board with dedicated slots for one type i.e. You would have two slots which support DDR3 and two slots which support DDR4 instead of having four slots capable of accepting DDR4 memory. You cannot put DDR3 in a DDR4 RAM. A DDR2 Ram won't be compatible with a DDR3 slot. About frequency:If the motherboard requires 1866Mhz RAM,then you can use any ram (but same type,here,it is DDR3 type) with frequency equal to 1866 or less than that. Motherboard will then operate at lower frequency. There have been motherboards that support both DDR2 and DDR3 RAM but you can only use one or the other at the same time. For example: MSI P45-8D. Not open for further replies.