Test Setup

All measurements were performed using ten electronic loads (seven Array 3711A [300 W each] and three Array 3710A [150 W each]) that are able to deliver over 2500 W of load and are controlled by a custom-made software. We also used a Picoscope 3424 oscilloscope, a Picoscope TC-08 thermocouple data logger, a Fluke 175 multimeter, and an Instek GPM-8212 power meter. Furthermore, we included a wooden box in our setup that, along with some heating elements, was used as a hot box. Finally, we had at our disposal four more oscilloscopes (Rigol 1052E and VS5042, Stingray DS1M12, and a second Picoscope 3424) and a CEM DT-8852 sound level meter. In this article, you will find more details about our equipment and the review methodology we follow. We conduct all of our tests at 40 - 45°C ambient in order to simulate with higher accuracy the environment seen inside a typical system; with the 40 - 45°C being derived from a standard ambient assumption of 23°C, plus 17 - 22°C being added for the typical temperature rise within a system.

Voltage Regulation Charts

The following charts show the voltage values of the main rails, recorded over a range of 60 W to the maximum specified load, and the deviation (in percent) for the same load range.

5VSB Regulation Chart

The following chart shows how the 5VSB rail deals with the load we throw at it.

Efficiency Chart

In this chart you will find the efficiency of the PT-650M at low loads and at loads equal to 20-100% of the PSU’s maximum rated load.

Voltage Regulation and Efficiency Measurements

The first set of tests revealed the stability of the voltage rails and the efficiency of the PT-650M. The applied load was equal to (approximately) 20%, 40%, 50%, 60%, 80%, and 100% of the maximum load that the PSU can handle. In addition, we conducted two more tests. In the first test, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 2 A, and, in the second test, we dialed the maximum load that the +12V rail could handle, while the load on the minor rails was minimal.

Efficiency is very high and the PSU had no trouble at all delivering its full power at 45°C ambient. The delta difference between input and output temperatures is small since the heatsinks in this unit are pretty small. The fan worked at high RPMs and made its presence felt despite the small delta difference, especially at higher loads. However, it wasn't annoyingly loud and PSU noise will most likely be fully covered by the output noise of all the other components in an air-cooled system.
FSP had to sacrifice tight voltage regulation, especially at +12V, in order to achieve the highest possible efficiency rating. The 3.3V rail was also only a hair away from the ATX limit at full load, something that had to do with its low initial voltage. Performance at the Cross Load tests is mediocre, to say the least.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the PT-650M at loads much lower than 20% of its maximum rated load (the lowest load that the 80 Plus Standard measures). The loads that we dialed were 40, 60, 80, and 100 W (for PSUs with over 500 W of capacity). This is important for settings where the PC is in idle mode with power saving turned on.

The new AURUM bars its teeth at the competition at low loads. Efficiency reaches 80% even with 40 W load, only to go through the roof at higher loads. FSP did, without any doubt, an excellent job of attaining the highest possible efficiency, regardless of load.

5VSB Efficiency

The ATX spec states that the 5VSB standby supply's efficiency should be as high as possible and recommends 50% or higher efficiency with 100 mA of load, 60% or higher with 250 mA of load, and 70% or higher with 1 A or more of load. We will take four measurements: three at 100, 250, and 1000 mA, and one with the full load that the 5VSB rail can handle.

This is amongst the most efficient 5VSB rails we have encountered so far, hands down. The efficiency readings of the first three tests are not that amazing, but the 88.25% reading with full load undoubtedly is.

Power Consumption in Idle & Standby

In the table below, you will find the power consumption and the voltage values of all rails (except -12V) when the PSU is in idle mode (powered on but without any load on its rails) and the power consumption when the PSU is in standby mode (without any load at 5VSB).

Vampire power is kept very low and barely exceeds 0.2 W, making this unit compliant with even the future ErP Lot 6 2013.