Circuit Analysis

The X370 SLI PLUS reveals its secrets when the heat sinks and shield come off.

The VRM is in an 8+2 phase configuration for the core and SOC power rails. The PWM controller is a 4+2 phase one from Richtek, the RT8894A. It offers three integrated drivers on the four phase channel, but none on the SOC channel. A Richtek RT9624F complements the three integrated one from the PWM, and two more RT9624F drivers are found driving the SOC rail.

To get eight phases from the four the PWM outputs, MSI just doubled the number of power stages components on each driver. Nikos PK616BA and PK632BA PowerPAK MOSFETs are used as the high-side and low-side MOSFETs. The capacitors are rated for 5K hours at 105C.

One of the Richtek RT9624F is on the back of the PCB behind the SOC rail power stages. A Richtek RT8125E single-phase PWM/driver IC controls the memory VRM. The memory VRM is a single phase with double the number of NIKOS MOSFETs.