The X99S XPOWER is MSI's top-of-the-line overclocking motherboard. The company has just introduced the X99S MPOWER to complement it on their product stack. It is a similar motherboard with a smaller price tag that was reduced by removing a few optional features (I will outline the major differences, below). These are basically unrelated to performance and overclocking, minus the buttons to set the base clock on the motherboard itself and a couple of accessories (the XPOWER comes with a free Delid Die Guard and temporary fan stand). It is more things like the number of I/O ports.
The main differences with the MPOWER are:
- It does not have the fifth, eight-lane PCIe slot, just the four provided by Haswell-E.
- It has one Intel Gigabit Ethernet adapter, instead of two.
- It does not have built-in 802.11ac WiFi or Bluetooth.
- It has two less USB 3.0 ports (external).
- It has one less USB 2.0 port (internal, seemingly the "Direct USB" port for BIOS updates).
- It does not come with a Delid Die Guard or fan stand.
There are a few other differences, such as the XPOWER having an I/O port cover and a few extra on-board overclocking switches and buttons, but I cannot see anything that stands out. The current price difference is about 115$ at Newegg, which is a healthy saving if nothing is a deal-killer.