Introduction

Rosewill is a company that started as a subsidiary and house brand of Newegg, focusing on simple components and hardware at very competitive prices. In time, the company fledged into a stand-alone company and expanded their product ranks to include a myriad of products from simple cables and adapters to advanced computer hardware, home appliances and office products. The sheer number of products Rosewill markets today is bordering on ridiculous. Nevertheless the company is strongly localized, with their products readily available only in the North American markets. Rosewill is making moves to enter other regions and some, but not all, of their products can also be found in Southeast Asia, Japan, China and Australia.

Today we will be having a look at the Rosewill Photon 1050W. This is the second model of the Photon PSU series which is aimed to advanced users and gamers. All the units of the Photon series are 80Plus Gold certified, have a single 12V rail and are fully modular without any hardwired cables. It is a large series, with units ranging from 550W up to 1200W - it is therefore extremely likely that not all of the units are based on the same platform, or even that they come from the same OEM. Therefore the results of this review should not be extended to reflect the performance of other units of the series.

The unit retails for $140 including shipping and the 1050W version of the Photon is significantly cheaper than most competitive products. The 1050W unit that we will review today boasts good features and warranty for its price range, yet there is a catch: it is rated for 1050W output at 40°C. This is not in any way illegal, as this is the normal rating for the operating temperature of consumer PSUs, but most of the competition rates their high performance units at 50°C. We do perform out hot testing with >45°C ambient temperature and as such we will soon see where the Photon 1050W truly stacks against the competition.

Packaging and Bundle

Rosewill supplies the Photon 1050 in a fairly sturdy cardboard box, with a simple and very dark artwork theme. The artwork is focused on a picture of the unit itself, surrounded by abstract imagery. Very basic information about the PSU and its features can be found around the sides of the box.

The bundled items are few, limited to some very short cable ties, four normal screws, an AC power cable and a very basic manual. The manual is so plain that the user would have to seek detailed information elsewhere, such as Rosewill's website. With the exception of the typical sleeved ATX 24-pin cable, the rest of the cables are "flat", ribbon-like, with black wires. There also is a very basic Molex to Floppy adapter, for those that still own legacy devices and want to power them with a $140 PSU.

External Appearance

The only thing that truly differentiates the Rosewill Photon from any other black PSU is the fan finger guard, which is not a separate part but an elongated honeycomb pattern punched on the steel chassis itself. Other than that, the series logo is printed on the right side of the chassis making it visible from a windowed side panel only if the PSU is installed with its fan facing upwards. There is absolutely nothing on the left side of the unit; the spectator will see only a plain, matte black surface from the side of a case if the unit is installed with its fan facing downwards. The sticker with the specifications of the PSU is found at the top side of the chassis.

Only the numerous connectors for the modular cables can be seen at the front of the chassis, with a basic printed legend indicating which connector corresponds to each cable. The CPU and PCI Express cables share the same connectors, while the split 10-14 pin connector is for the 24-pin ATX cable and the smaller connectors are for SATA/Molex cables.

Internal Design

A black 135mm fan from Globe is responsible for the cooling of the Photon 1050W. The B1352512H is a ball bearing fan with a maximum speed of 1500RPM, meaning that it can get significantly loud if the unit is heavily stressed. Of course, a thermal control circuitry adjusts the speed of the fan according to the load and the temperature of the unit, so we will examine how it truly behaves during our testing.

A look inside the Rosewill Photon 1050W instantly reveals that the OEM behind this unit is Sirfa, This is the same company who owns High Power as their own retail brand. Sirfa is not a bad OEM at all but it is not yet highly reputable among enthusiasts, mostly due to a few not-so-good low-cost designs they supplied through Sirtec in the past. The filtering stage is textbook, with four Y capacitors, two X capacitors and two filtering inductors. We also found a transient suppression diode and a classic fuse. There are two main rectifying bridges, sandwiched on a small, dedicated heatsink. Two large Nippon Chemi-Con 400V/390μF capacitors can be seen in the PFC stage, alongside an equally large filtering inductor. Two low resistance power transistors by Infineon form a half-bridge primary inversion stage, while eight transistors by the same company create the secondary conversion stage and generate the 12V output.

Quality wise, the Photon 1050W ranks above average, but it is not perfect. The quality of the components is outstanding; all of the main components come from reputable manufacturers - the electrolytic capacitors are all from Nippon Chemi-Con and the polymer capacitors are supplied by Fujitsu Electronics. Sirfa could improve their design and assembly quality a little though -  the design is a little messy and there are several joints amateurishly soldered. These will not be a problem but they are also not something enthusiasts like to see in products that are supposed to compete in the high-end segment of the market. 

Cold Test Results

For the testing of PSUs we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M 40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.

Even though only barely, the Rosewill Photon 1050W does honor its 80Plus Gold certification badge. The energy conversion efficiency reaches 92.2% at 50% load, with an average of 90.7% within the nominal load range (20% to 100% of the unit's capacity). At low loads the unit performs very well, maintaining an efficiency of 85.6% at 10% load and 78.5% at just 5% load.

The thermal control circuitry of the Rosewill Photon 1050W seems to favor acoustics over thermal performance, allowing the internal temperatures of the unit to get a little higher so that the fan will not be as noisy. At room temperature, the Photon 1050W is almost entirely inaudible up to 50% load, which is an output of over 500W. After that point however, the fan will start increasing its speed sharply and becomes clearly noticeable.

Hot Test Results

By the results presented in the following tables, the Rosewill Photon 1050W offers good power quality, especially considering the temperatures that the components reached inside our hotbox. The maximum ripple on the 12V line was 56mV under full load, a fair figure considering that this is a unit rated for operation at 40°C. The 3.3V/5V voltage lines fared better, with the maximum ripple being 22mV/24mV respectively. Voltage regulation is very good, at just 1.2% for the 12V line and about 1.6% for the minor lines.

Once again, we need to mention that this is a PSU rated at 40°C and we perform our testing at temperatures higher than 45°C - we could reduce the ambient temperature of our hotbox testing but we chose not to do so as the results would then not be comparable to those of our previous reviews.

The high ambient temperatures have a significant impact on the electrical performance of the Photon 1050W, reducing its energy conversion efficiency by an average of 2%. The drop is higher as the load increases, reaching a massive 3.7% drop with a load of 1050W. Considering that the ambient temperature is almost 48°C at this point, these actually are overload conditions for the Photon, meaning that its capability to maintain good power quality and keep operating with such a load is a victory all by itself.

By looking at the internal temperatures of the Photon 1050W, one can easily realize who the culprit behind the dropping efficiency is. This is one of the hottest PSUs we have ever tested. With the temperature of the secondary side heatsink surpassing 100°C under maximum load and the primary side heatsink following closely, it is easy for anyone with basic electronics knowledge to deduct that the exceedingly high temperatures at the very least increase the resistance of the components. The cooling fan is now audible even at low loads, with its speed constantly increasing to keep up with the increasing energy losses. Even though it jumps at maximum speed when the load is about 900 Watts, it cannot stay ahead of the curve with the heavy energy losses. 

Conclusion

With the Photon 1050W, Rosewill attempts to lure enthusiasts and advanced users with the promise of high quality and performance at an affordable price tag. After all, competitive pricing is the foundation of Rosewill's market strategy. With a retail price of $140 including shipping, the Photon 1050W is one of the cheapest modular 80Plus Gold units with that kind of power output. The target group that the Photon is aiming to however is not easily swayed by a low price tag - most enthusiasts would gladly pay a little more to get something better.  So one must consider the true question of where exactly the Photon 1050W stands.

The retail price of the Photon 1050W is competitive but there is a catch - this unit is rated for continuous operation at 40°C. If it were to be rated at 50°C, as most of the competition does with their high-end units, it would most likely end up with a 950W-980W label. Competitive units that boast the same power output at 50°C are, bluntly put, more powerful. The Photon 1050W did reach its specified maximum power output inside our hotbox, yet not without signs of overloading and reaching temperatures that could turn water into vapor.

For those seeking quality, the Photon 1050W will not disappoint. We found some of the finest components inside, from all-Japanese capacitors (including the polymers) to the microchips. Sirfa performed a good assembly job, although not the best we have ever seen but surely much better than that of their usual low-cost unit. Even the fan, although it is a simple model, comes from a seasoned and reputable manufacturer.

When it comes to performance, the Photon 1050W left us with mixed feelings. It does perform very well in room temperature, confirming its 80Plus Gold efficiency certification and staying almost inaudible up to 50% load. When the ambient temperature is high however, there is a cascading negative impact on the electrical, thermal and acoustic performance of the unit. Despite the presence of a powerful fan that is trying to catch up, the Photon 1050W does get very hot and that reduces the efficiency of the components, which then produce greater energy losses and make the unit even hotter and louder. Remarkably, even under such conditions the output power quality remains very good, with the Photon 1050W maintaining great voltage regulation and good ripple suppression. These figures are much lower than the ATX design limit and would be very good for a mainstream product; however, this is a PSU trying to entice enthusiasts and other advanced users away from other high end units which can be leagues ahead when it comes to power output quality, especially at high ambient temperatures.

The Photon 1050W is a well-made fully modular PSU, capable of good overall performance and retails at a competitive price ($140 shipped at the time of this review). It is however difficult to find supporters in the user group it is meant to attract. If all someone cares about is to get a good quality 1000-1050W PSU that works well for the lowest possible price, then the Photon 1050W becomes a plausible option. If however a user is looking for class-leading electrical performance and or inaudible/low-noise operation, they will probably have to dig a little deeper into their pockets.