Summary: Zalman ZM500-RS is the company’s most recently released power supply unit and promises a high power conversion efficiency (80 plus bronze) in combination with a minimal noise level.

INTRODUCTION

The new series of power supplies recently released by Zalman ha a “RS” suffix in its name which stands for “Resonant Switching”. Compared to Two-Forward Switching, the more advanced Resonant Switching minimizes “switching loss” reduces heat generation, and operates more efficiently by eliminating the need for an output inductor leading to outstanding stability and reliability.

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With the use of “Resonant Switching” it is possible to use smaller components which don’t generate as much heat. Thus, it’s possible to use o less noisy cooling solution. As the RS technology minimizes the loss of power in the conversion, this can be considered a very “green” and energy saving product.

OK, so let’s have a look at the specifications:

The RS-series also includes a 600W model perhaps more adapted to high end components. The RS-series will without a doubt be very appreciated by builders of compact systems, the only thing I miss is a modular design for the wiring.

FIRST IMPRESSIONS

The unit comes in a nice looking cardboard box with a lot of printing on it which emphasizes the most important characteristics of the power supply.

In the back side of the box, Zalman has put some images of details such as the wiring and used components. They have also placed summaries in different languages of the most important specifications.

In the box I found the power supply (perfectly protected); a power cable; some plastic bridles; screws and the manual.

ZALMAN ZM500-RS IN DETAIL

One of the first things that I noticed about the Zalman ZM500-RS is that it’s smaller than normal PSUs. Of course it still follows the ATX standard in terms of where the screws are placed and everything else. It’s just not as bulky as what I am used to, which makes it ideal for smaller dimensions cases.

The side with the power cord connector and the on/off switch has a metallic grid to increase the air flow. The right side has the Zalman logo engraved in it. The opposite side holds a big tag with all the specifications of the power supply.

The cooling solution consists of a 120mm fan which runs at a constant speed (not heat regulated). Of course I had to take the top cover off and take a look. I found out that this PSU is actually assembled by POWER LOGIC which is a well know builder of PSUs, used by other players like Xigmatek and Asus.

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The wiring of the Zalman ZM500-RS is contained by strong acrylic plastic which holds it firmly in place. The length of the wiring is sufficient for an average tower case but I wouldn’t recommend using it with full tower cases.

TESTS OF ZALMAN ZM500-RS

This will be one of the last reviews I do with my usual test system setup, never the less, here are the specifications:

To realize the test I used OCCT 3.1 to load the system to the max. In order to measure the voltages I used an ordinary digital multimeter and the power usage was measured with the ZM-MFC3 which I reviewed last week. The results can be viewed in the graph below:

As you can see from the graphs, the numbers the Zalman ZM500-RS produced are excellent. The voltages are tremendously stable; the PSU remains totally capable of delivering the power as it should even at full system load. The total consumption at full system load is the lowest I have measured with my system, which surely is a result of the Resonant Switching technology.

The noise emitted by this PSU is almost not possible to hear, that is just how quiet the fan is and because the fan turns at a constant speed the load doesn’t affect the noise emission.

CONCLUSIONS

Doubtless the Zalman ZM500-RS is a high quality power supply with many interesting characteristics. I love that it’s small which makes it perfect to put in a small HTPC case or any other smaller PC case. However, the wiring is rather short so if you are building a PC system in a full tower case you will probably not be able to use this PSU without any extension cables.

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The performance is absolutely fantastic, it is in fact the most energy efficient PSU I have tested so far. The energy efficiency is of ever increasing importance and it’s nice to know that your system is using up the minimum amount of power, which will in the end mean minimal cost. The PSU is ultra quiet and the voltages are stable no matter what you throw at it.

Zalman has done a great work with this product; the RS technology is a smart innovation that will save you money in the long run. The price of the ZM500-RS goes up to around 90€ which is a lot of money for a PSU. It is clearly aimed towards PC builders with a bigger budget or anyone interested in its power saving or low noise features.

Good:

• Overall quality
• Size, ideal for smaller dimension cases
• Energy saving technologies
• Stability and efficiency
• Very quiet cooling solution

Bad:

• Modular wiring would have been nice
• Short wires could cause problems

The final score is 90 out of 100 owls, and we give the “Zalman ZM500-RS″ our Editor’s Choice Award.

Thanks goes out to Zalman for letting me review this PSU.

Author: Manuel González Fernández

Translator: Vince Emiloz Sanderson

Antec EarthWatts 500 Watts, Helping the Earth

Antec is one of the most important manufacturers of PSUs. It has had great success in the technology market and has been well known for providing excellent products for many years. The company has joined the urgent cause of saving the Earth, offering products with incredible energy efficiency.

Introduction

With its EarthWatts PC power supply, Antec has committed itself to saving energy and maximizing performance.

Antec is doing its part to preserve the environment. As we all know, It’s more important than ever to save our planet. That’s why Antec has brought out these PSUs, focusing on saving energy while it saves consumers money. They incorporate the EarthWatts Active PFC, which includes an advanced energy-saving system. You’ll see this reflected on your electricity bill, and it will also help protect the environment.

First Look

A quick look shows a simple package with earth tones, which probably refer to Mother Earth.

The back side lists the product’s more outstanding features. These days, one of the most important is that this power supply has an efficiency rating of at least 80%.

When taking the product out of its package, we see a power supply with a very simple finish, almost like those on generic products of this type. But the most important thing about this one is its efficiency.

When looking at the wiring, we see a panel-type grill (like the cells in a beehive). This type of grill provides better ventilation for the heatsinks inside the PSU.

Specifications

• · 80 PLUS ® certified. This reduces operating costs and protects the environment.
• · Low-noise 80 mm (3.15″) fan.
• · Dual 12V: 12V2 for the circuit board and peripherals, 12V1 for the processor
• · Circuit protection prevents damage from short circuits, voltage spikes, high voltage, and low voltage.
• · The EarthWatts’ precision power lets it deliver its full nominal potential (24 hours a day, nominal at 50ºC [122 ºF]).
• · Active Power Factor Correction (PCF) of up to 99%.
• · Dimensions: 8.6cm / 3.4″ (H) x 15cm / 5.9″ (W) x 14cm / 5.5″ (D).
• · Weight: 1.86kgs / 4.1 lbs.

Connectors

ATX main (20/24 pin)
ATX 12v (4 pin)
EPS 12v (8 pin)
2x PCI-E (6 pin)
4x SATA
Floppy Drive (4 pin)
6x Molex (4 pin)

Test and Results

Tests:

1. Voltages were read with a multimeter from each of the power supply’s outputs for over 20 minutes, to see if they were constant, and to determine the linearization curves of each of the outputs.

2. We checked to see if the voltage lines were constant when we overclocked our system.

As we can see in both the graphic and in the table, there are voltage variations in the 3.5 volt, 5 volt, and 12 volt lines. But these are not significant, because tension is always lost in every electric or electronic system. I think it’s good to mention that the electronic circuits that Antec uses to build its power sources have a margin of +- 10 % for voltage drops, so this doesn’t present any problem when operating the 500-watt EarthWatts power supply.

Test 2

Power Supply Capacity in Overclock.

One fundamental characteristic of a good power supply is that it can tolerate some good overclocking. For this, we used the power calculation tool provided by Antec at www.antec.outervision.com to see if our hardware falls within the parameters of the 500-watt EarthWatts PSUs.

After using Antec’s power calculator, which said that our system was within parameters, we then overclocked the system.

So far, so good. We just need to measure voltages in the lines to obtain the following graphic:

CONCLUSIONS

The results were very good. All voltages operated within limits. During the test, the power source’s fan remained calm. It operated at high velocity during the “overclock con carga” test (“overclock with load” — “sin carga” means “without load”), which can be very demanding. The test system remained stable and reliable throughout all load testing and in daily use. This was truly a very demanding test platform.

In general, the Antec EarthWatts is an incredible power source. It $80 price is somewhat expensive, but you’ll get great stability, and it works quietly, with low energy consumption. One thing we didn’t like, and that kept this unit from scoring higher, was the lack of things such as sleeving and/or modular cables, as well as the product’s finish, which could be confused with that of generic PSUs.

The final score is 86 out of 100 owls and we give the “Antec EarthWatts 500 Watt Power Supply” our Recommended Award.

Translated by Ed Winograd

Written by Juan Baldemar