Efficiency

Using the efficiency results from the previous page, we plotted a chart for the LX600's efficiency at low loads and loads equal to 20% -100% of the PSU's maximum-rated load.



Under light loads, efficiency is low, and the LX600 is as efficient as other Bronze units of a similar capacity with normal loads.

Efficiency at Low Loads

In the next tests, we measure the efficiency of the LX600 at loads much lower than 20% of its maximum-rated load (the lowest load the 80 Plus Standard measures). The loads we dialed were 40 W, 60 W, 80 W, 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 PSU only cracked the 80% mark during the last two light-load tests, which didn't surprise us given its Bronze certification. If you want higher efficiency at light loads, avoid Bronze units and look at Gold or Platinum PSUs instead. Such units are obviously much more expensive.

5VSB Efficiency

The ATX specification states that 5VSB standby supply 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, each, and one with the full load the 5VSB rail can handle.

Given this is a PSU for users on a budget, the 5VSB rail's efficiency is decent.

Power Consumption in Idle & Standby

In the table below, you will find the power consumption and 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 low, which is why the 5VSB rail is so efficient at light loads.

Fan RPM, Delta Temperature & Output Noise

The cooling fan's speed (RPMs) and the delta difference between input and output temperature are illustrated in the following chart. The following results were obtained at 38 °C - 45 °C ambient.



A chart that shows the cooling fan's speed (RPMs) and output noise follows. We measure the fan's noise from one meter away, inside a small custom-made anechoic chamber whose internals are completely covered in specialized soundproofing material (Be Quiet! Noise Absorber Kit). Background noise inside the anechoic chamber was below 20 dBA during testing, and the results were obtained with the PSU operating at 38 °C - 45 °C ambient.



The following graph illustrates the fan's output noise throughout the PSU's entire operating range. The same conditions of the above graph apply to our measurements, but the ambient temperature was in-between 28 °C and 30 °C.



Bronze units have a higher thermal signature than Gold- or Platinum-certified PSUs, especially at high loads, which makes the LX600 surprisingly quiet overall. You should look for a Gold-certified unit if you want a budget PSU that is even quieter. However, such a PSU will probably also cost more.