The CoolerMaster RS-460-PMSR-A3 power supply is a basic low cost generic 400W ATX PSU, Its sold mostly into the repair and maintenance market.

To make things worse for reviewers, there are four kinds of power supplies on the new eXtreme Power Plus series: the ones using an 80 mm fan on the rear of the unit (model names starting with “PMS”) and the ones using a 120 mm on the bottom of the unit (model names starting with “PCA”), and the ones without PFC (model names ending with “R”) and the ones with passive PFC (model names ending with “P,” are sold to the European market). For the 460W series there are four models (PMSR, PMSP, PCAR and PCAP) and the RS-460-PMSR-A3 model lacks PFC and has an 80mm fan on the rear.

This model is designed for field replacement for an older machine. While more sophisticated compared to the OEM PSU, the RS-460-PMSR-A3 is still a basic PSU albeit with some support for a video card. The machine the PSU is being used in lacks a video card slot so this PSU is actually exceeds the needed power capacity.

The  RS-460-PMSR-A3 is the standard ATX 2.3 W/O PFC and is 86 mm by 150 mm at the back panel to fit the standard ATX screw positions. The RS-460-PMSR-A3 is the standard 140 mm deep which is allows for lots of room for DVD drives and the cable assembly. The  RS-460-PMSR-A3 uses a pair of 12V circuits to reduce costs. Typically one rail is used for the motherboard and the other supplies the PCI Express supplemental power. The overall quality of the components is very basic. The RS-460-PMSR-A3 uses a 80mm ball bearing fan to keep the assembly cool.

The PCI Express cable is a 6-pin capable of supporting a single display adapter. This PSU is best off with integrated video or a low-end video card. With 400W of power, options are comparatively limited. Low end motherboards like our Asus M2N-VM CSM only need a 4-pin CPU power cable which is what this PSU is best at.

The RS-460-PMSR-A3 has a gun metal grey paint and the air flow is linear from the front and exhausting through the rear. The small fan is typical with lower capacity power supplies. More expensive models use larger 120mm and 140mm fans which are less noisy and more efficient.

The RS-460-PMSR-A3 is an older design that uses separate circuits to each of the voltages. More modern designs now use DC-DC converters drawn from the 12 V line. The PSU also lacks many other modern features which come from the older ATX design standards.


  • ATX 2.3 W/O PFC
  • 400W maximum capacity


CoolerMaster RS-460-PMSR-A3 ATX Power Supply
AC Input Rating DC Output Rating
AC Input: 100V – 240V DC Output +3.3V +5V +12V1 +12V2 -12V +5Vsb
Current: 8A Max Load 22A 25A 18A 18A 0.5A 2.5A
Frequency: 50Hz – 60Hz Maximum Combined Wattage 180W 200W 200W
Total Power: 400W

A total of 3 different connector strands are available with the CoolerMaster RS-460-PMSR-A3.

  • 2 Molex cables with 3 connectors
  • 1 SATA cable with 3 connectors
  • ATX12V 4-pin connector
  • 1 PCIe 6-pin connector

One of the Molex strands has a Berg connector for a floppy drive. There is only the ATX12V connector, so its underpowered for the M5A99FX motherboard.


We tested the PSU with the Asus EAH5450 512MB HDMI and the Asus M2N-VM CSM motherboard. The PSU operates the machine fine, we then returned the PSU to the Acer machine for long term use.

Software monitors showed the PSU to be within range even when playing demanding games. The PSU seems to be well within ATX tolerances. We use Asus motherboards and they feature a complete sensor set to monitor all power levels. The EAH5450 uses a maximum of about 25W which represents the typical load seen with the bottom of the line video cards. The old Acer machine lacks sensors to monitor the power.


We connected the power meter to the PSU and the power consumption suggests the CoolerMaster RS-460-PMSR-A3 can barely meet basic 50% efficiency at a 40% load which is below the EPA Energy Star 5 program requirements. This power supply is low end so we do not place high expectations on it. The long service life has been the biggest feature.

This PSU lacks active power factor correction which really hurts the efficiency.