Big thank you to CryoPC for providing the following test rig:
CPU: Core i5 750 @ 4GHZ
Motherboard: Asus P7P55D-E
GPU: Sapphire 5850 1GB
RAM: Corsair Dominator 4GB PC3-12800 DDR3
Storage: Samsung F3 500GB 16MB
CASE: NZXT Hades
Here at XSReviews, we don’t have the money for a full test bench when it comes to PSUs. Load testers cost thousands of pounds which unfortunately we just don’t have. Because of this, we don’t pretend to test the rail stability or efficiency of a PSU, as we simply can’t do it effectively.
However, what we can do is test the Ripple/Noise quality of each rail using an oscilloscope. The one used was USB Instruments Stingray DS1M12 using HP 3060 probes and also in line with ATX specifications, I used 10uF and 0.1uF capacitors to simulate added load.
Noise and Ripple
The last PSU review I did included a pretty good explanation of Noise/Ripple, so if you don’t mind I’ll just reproduce that here instead of rewriting it:
“So what is noise and ripple? This is the description of minute voltage fluctuations on each of the main rails in any PSU. In a nutshell, the good power supplies have very little, the awful ones fluctuate a lot. According to ATX Specifications, there shouldn’t be more than 120mv in peak to peak voltage fluctuation on the 12v rails, and no more than 50mv on the 5v and 3.3v rails. These are the theoretical maximums, with good PSUs hitting somewhere under half, so 60mv and 25mv respectively.
If noise and ripple are present in abundance, you’re most likely going to find it at full load. Not posessing a load tester, the best I was able to do was to load up Furmark and WPRIME to max out the test rig. This ended up drawing 414w from the mains. This will likely equate to nearly 10% less used by the PSU because no power supply is 100% efficient. All we have to go on here is the 80 PLUS platinum rating of the PSU, which under 50% load conditions should be around 93%.
All images are of the average fluctuations. Not posessing a hot box to ensure that the unit is tested under stressfully heated conditions, air intakes and exhausts were partially covered. The internal temperature of the PSU was then measured using a probe, with results taken when it reached 40 degrees centigrade.”
Since I used the .01v scale, each line on the graph represents 0.02v, or 20mv.
Numbers on the left of each image to take note of are the bottom peak to peak frequency results.
All rails are within specification, so no problems here.
I’d love to be able to test this PSU a bit more, perhaps efficiency or overload as it comes packing a lot of interesting features. I quite like the new modular connectors and the cables in general are well put together. The only problem I did have with them was the 4+4pin, which was really difficult to get into place. I ended up having to glue the two sections together.
One feature to take note of is the silence of this unit. Until it hits 70 degrees C, the fan doesn’t even kick in. This is a quiet performing unit, completely silent until things get hectic.
As for Noise/Ripple, there were no issues with the Golden King and it should be perfectly safe to use. It’s high efficiency rating is confirmed on the Plug Load Solutions site though interestingly, not in the 230v category.
The only real caveat here is the price. At £175 this could be the most expensive 550w PSU available right now. In our tests it does very well and of course it’s efficient, but is it worth that much?
Would I pay that? No. If I had enough that money wasn’t an option? Maybe.
Very high efficiency rating