MSI Big Bang XPower Motherboard

Voltage Regulator

MSI Big Bang XPower comes with the most high-end voltage regulator circuit we’ve seen to date. This circuit has a total of 16 phases for the CPU main voltage (Vcc a.k.a. Vcore), two phases for the CPU VTT voltage (memory controller, QPI bus controller and L3 memory cache), two phases for the north bridge chip (IOH) and two phases for the memory. Therefore it uses a “16+2” configuration.

Comparing only the number of phases is unfair, though. Each phase from this motherboard switches at a higher frequency (1 GHz instead of 250 MHz) and has a lower switching loss, resulting in a higher efficiency (above 93%) and lower operating temperature. This is achieved by using an integrated circuit (FDMF6704V) called DrMOS instead of discrete transistors. According to MSI each DrMOS phase is equivalent of four regular phases, so the “16+2” configuration used by this motherboard is comparable to a “64+8” configuration using the standard voltage regulator architecture used by competing products!

If this was not enough, MSI decided to use military-grade components on the voltage regulator circuit. Electronic components rated as military-grade have a higher operating temperature range, tighter specs and higher life-span. All electrolytic capacitors used on the voltage regulator circuit are SMD (surface mount device), also known as highly-conductive polymerized or simply Hi-c, and solid ferrite chokes, which MSI is promoting as “icy chokes” or “super ferrite chokes.” According to MSI these chokes work  20&deg
; C cooler than traditional chokes. Please read our Everything You Need to Know About the Motherboard Voltage Regulator tutorial for more information.

Capacitors used outside the voltage regulator circuit are solid.

Figure 10: Voltage regulator circuit with the heatsink.

Figure 11: Detail of the SMD capacitor, solid choke and phase integrated circuit.

Besides having a high-end voltage regulator circuit, Big Bang XPower can disable phases from the voltage regulator circuit as needed in order to save energy, feature called APS (Active Phase Switching). A group of LEDs near the memory sockets indicate how many Vcc phases are active at any given moment. The motherboard also has LEDs to monitor the number of phases being used on the chipset voltage regulator, on the VTT voltage regulator (called QPI by the manufacturer but this phase also feeds the memory controller and the L3 memory cache) and on the memory voltage regulator.

Figure 12: LEDs to monitor the number of Vcc phases being used.