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.

Main Output
Load (Watts) 212.08 W 528.3 W 788.6 W 1047.54 W
Load (Percent) 20.2% 50.31% 75.1% 99.77%
Line Amperes Volts Amperes Volts Amperes Volts Amperes Volts
3.3 V 4.17 3.37 10.44 3.35 15.66 3.33 20.87 3.31
5 V 4.17 5.13 10.44 5.09 15.66 5.07 20.87 5.05
12 V 14.61 12.09 36.53 12.05 54.8 11.99 73.06 11.95


Line Regulation
(20% to 100% load)
Voltage Ripple (mV)
20% Load 50% Load 75% Load 100% Load CL1
3.3V + 5V
3.3V 1.6% 8 12 18 22 12 26
5V 1.55% 10 16 22 24 16 26
12V 1.2% 20 32 44 56 54 20

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. 

Cold Test Results Final Words & Conclusion


View All Comments

  • Oxford Guy - Wednesday, March 25, 2015 - link

    It would be nice to see a review of the Corsair RM 850. Techpowerup's review suggests that it is the quietest actively-cooled PSU available. While they gave the RM 750 an even better rating for the average noise level throughout its operating range, the 850 delivers more watts before noise ramps up. So, it appears to be the best option for those who want to avoid noise while still having the ability to go beyond what passive PSUs offer.

    However, the concern is the quality of the capacitors primarily. It would be good to see another review site verify or contradict Techpowerup's results.
  • gsuburban - Sunday, June 28, 2015 - link

    Yes. I've heard the Corsair RM model's are debatable because they are manufactured by Great Wall or some other maker. Folks tend to suggest on the Corsairs made by Seasonic are worthy such as the AX models. I haven't had any issues with their TX and TX-v2 PSU's in the past years but now the RM has replaced those. There's lot of features with the RM and reviews give them high points for total output accuracy while some say they a few percentage of them don't last or have problems.

    It would be reasonable to ask many of the hardware review people to do long term 60% power usage with daily on-off cycle testing combined for a final determination of longevity and/or problems. Most will say all PSU's loose total power output after a few years which stands to say why folks should purchase a PSU with about double the power they really need to allow for that and to allow the unit to operate and full efficiency.

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