EVGA Classified SR-2 Motherboard

Voltage Regulator

The EVGA Classified SR-2 uses two separate voltage regulator circuits for each CPU, each one with eight phases for the main CPU voltage (Vcc, a.k.a. Vcore) and two for the CPU VTT voltage (used by the integrated memory controller, L3 memory cache and QPI bus controller). Thus each CPU has an “8+2” voltage regulator.

This number seems “low,” but that is not the whole story, because the voltage regulators use high-end components to generate the main CPU voltage. Instead of using discrete MOSFET transistors, EVGA opted to use a Volterra VT1185SF integrated circuit on each phase that has necessary transistors embedded in the same fashion that MSI uses “DrMOS” integrated circuits on their high-end motherboard. Unfortunately Volterra doesn’t post details of this integrated circuit on their website. Each phase also uses solid chokes and SMD (surface mount device) electrolytic capacitors, also known as highly-conductive polymerized or simply Hi-c (these components are soldered on the solder side of the motherboard). The voltage regulator for the VTT voltage uses standard ferrite chokes and solid capacitors (all other capacitors used on this motherboard are solid).

Figure 13: Detail of the Vcc voltage regulator.

Figure 14: SMD capacitors.

This motherboard also has a three-phase voltage regulator for each memory bank (usually high-end motherboards use a two-phase regulator for the memories).