Efficiency

Using the efficiency results from the previous page, we plotted a chart showing efficiency of the ZM1350 at low loads and at loads equal to 20-110% of the PSU's maximum rated load.



For a discussion of these results, see the text at the end of the previous page.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the ZM1350 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.


Efficiency at low loads is this overall good unit's Achilles heel. This is one of the rare times we measured efficiency below 60% with a 40 W load. Only with an 80 W load did efficiency surpass 70% and even a 100 W load only produced efficiency close to the 80% mark. This PSU is definitely not for a system that will operate at idle most of the time. Also, the fan operated close to its maximum speed during these low-load tests which produced a lot of noise, although the ambient was kept below 40°C.

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: one at 100, 250, and 1000 mA, and one with the full load that the 5VSB rail can handle.


This unit's efficiency is dramatically low at 5VSB, and you will find out why below.

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).


Strangely enough, this unit isn't ErP Lot 6 2010 compliant since it consumes much more than 1 W in standby mode. Normally, all electronic products, including PSUs, that are sold in the EU must follow the ErP Lot 6 2010 directive, which greatly restricts a product's carbon footprint. Such high vampire power has a big negative effect on the efficiency of the 5VSB rail.

Fan RPM, Delta Temperature and Output Noise

In the following chart illustrates the cooling fan's speed (RPMs) and the delta difference between input and output temperature. The following results were obtained at 40°C - 45°C ambient.



A chart that shows the cooling fan's speed (RPMs) and its output noise follows:



The fan profile is really aggressive and forces the fan to operate nearly at its full speed once the ambient hits 40°C. The funny part is that its speed hikes up again, to a staggering 4200 RPM and a noise output of 61.3 dBA, once you enable its turbo mode through the push of a button!