Raidmax Cobra Power 500W Power Supply Review

We tread off the beaten PSU path today with a power supply from Raidmax that is part of the Cobra series. The RX-500AF-B unit sports 500 watts of "Haswell Ready" power, a Bronze efficiency rating, advertised stable voltages, a "strong single +12V rail for high-end system heavy load configuration," plus a paint ball stained exterior.

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Conclusions

The Raidmax Cobra Power 500W is one of the few Raidmax branded power supplies we have had the opportunity to look at, though we have seen a pair of Sigma branded units. It is also the smallest capacity Raidmax power supply we have seen. Interestingly, this is somewhat like what we saw with our recent EVGA reviews. We first saw a high powered top of the line unit which fared poorly and then saw a 500W unit that was very much entry level. With the EVGA example, this worked out "OK" for the 500W model as it was a much more competent product than the top of the line product. Today, with the Cobra Power 500W, are we going to see the same thing from Raidmax? Indeed, when we back the power level and features down a bit does Raidmax deliver a serviceable product? Let's see.


HardOCP’s testing methodology is intended to very much push power supplies to their advertised wattage rating in temperatures that will represent some of the hottest computer enthusiast cases. So if a unit passes all our testing it is definitely not something to take lightly. In fact we expect more power supplies to fail our testing than make it through unscathed.

Build Quality

Overall, the build quality of the Raidmax Cobra Power 500W leaves a lot to be desired, including some way to escape 2008 (paging Snake Plissken). Certainly bargain/value/low end units will have certain compromises that are made in order to hit price points, but at some point too much is too much to sacrifice. With the Cobra Power 500W, we may have found "too much." Starting things off, we get a very CoolerMaster-esque juvenile finish on this unit with the hideous neon color scheme. The only redeeming value to this color scheme is that it is constrained to the large stickers on the unit which you could, conceivably, peel off leaving you with a flat black power supply. Once you get that taken care of, you are left with a very run of the mill black finish, normal overhead fan layout (but fluorescent colored), and fixed cabling. The housing itself though is very thin and bent during our usage and testing. When we moved to the interior of the unit, we found that, like recent comparable units, the design is very old but unlike with the EVGA 500B it is somewhat more lacking. Sure both units are far shorter than the housing used and both are old double forward primary with group regulated secondary designs on single layer PCB's, but this unit is even more sparse than that unit was. In addition to this sparseness, this particular unit was originally designed as a dual 12v rail unit and has had an ugly bit of soldering done on the secondary to change that. We also find very low end component selections with the capacitors being provided by Teapo and JunFu along with a fan from ShenZhen Poweryear Electronics Co., Ltd . Making these low end component choices even scarier is the fact that we get absolutely no documentation with this unit and, to the best of our ability to figure out, you get a one year warranty with this power supply. From a business standpoint, the shorter the warranty on this unit probably the better for the people selling it. For the people buying this unit, well....Yikes!

Load Testing

Today, the load testing results for the Raidmax Cobra Power 500W are a mess overall and these don't live up to the even lowered expectations we have for "entry" or "budget" offerings. The thing is, this unit never even started off with much in the way of good results. Among the most striking early results was with the voltage regulation which saw the 5v rail drop by 0.3v during testing! That change is three times what the 12v and 3.3v rails did. For the 12v rail, 0.1v isn't a bad change but for the 3.3v rail 0.1v is not good at all today. OK, well, that is all the bad news on the voltage regulation; right? Wrong! The last kick of sand was the fact that the +5vsb dropped to hit the ATX12v specification limit on the nose. The somewhat unfortunate thing is, these results actually allow this unit to end mixed compared to the already mediocre EVGA 500B because that unit saw worse 12v regulation. So, while really bad, this unit manages to end up looking like it was punching above its weight. That did change somewhat when we swung around to the efficiency results which saw the 120v results range from 77.13% to 81.90% and the 100v results range from 74.90% to 80.60%. On top of that, the 80 Plus results were 76.38%-83.01%-78.30% which completely misses the 80 Plus Bronze category at every step by a lot. How anyone could claim this unit was an 80 Plus Bronze power supply is just unfathomable.

While the regular load tests results for the Raidmax Cobra Power 500W were not good, the Transient Load Tests results were even worse. When directly loaded, the 12v rail showed a peak change of ~560mV and the 5v rail had a peak change of ~240mV! Read those again so you don't miss that, ~560mV! The unloaded 5v peak change during the 12v load was ~180mV which, relative to the other values, was decent. These results put this unit behind the rather marginal EVGA 500B. There just isn't any way for these results to seem worse than the absolute values indicate, except for the fact that the 12v rail actually dropped outside of the ATX12v specification limit in the process. Yeah, the load testing results for this unit are making that EVGA 500B look like a premium power supply right now.

DC Output Quality

In what is probably one of the high points of the day, we can firmly say that the Raidmax Cobra Power 500W posted mediocre but passing DC output quality. The only problem is, the peak values of ~50mV on the 12v rail, ~30mV on the 5v rail, ~20mV on the 3.3v rail still trail the EVGA 500B. The ripple/noise values started off in rather good shape too, these just ended up doing a bit worse than what we saw from the EVGA 500B and worse than what these needed to do to start to turn things around. As it stands, the DC output quality is not great, but it is passing and that is about as good as it gets today among the absolute metrics we have.

Noise

Skipping the usual pleasantries about product placement and features, when it comes to noise output we are just going to go straight to the fact that this unit was bizarrely quiet. Really. The Raidmax Cobra Power 500W was quiet in all of our testing even though it has a completely unknown fan (although it is a sleeve bearing), awful efficiency for modern times, and it was generally just a low end build all around. Perhaps the fan controller on this unit had just one speed, barely on, and that can explain the lack of noise output. Whatever the reason, the Cobra Power 500W was surprisingly quiet, though it seems that given the component selection, poor efficiency, and possibility that it is "so quiet" due to a far too passive fan controller this might not make the best solution for quiet cooling environments. Particularly where people are, perhaps, already dropping the airflow and using more efficient components to control noise output. So, be sure to weigh all of that before deciding how to jump with this unit.

Paul's Thoughts:

Sure, the most recent comparable 500W unit we have seen (the EVGA 500B) was by no means a good power supply, but it did at least have the distinction of being a better power supply than what we last saw from EVGA and being a passing unit. Today, the Raidmax Cobra Power 500W has the potential to follow much in the same pattern as the last Raidmax unit we saw (the RX-1000AE) was not a good unit and the follow up product we are looking at is a 500W "80 Plus Bronze" unit. The similarities, though, end right about there unfortunately. Where the 500B was able to pull out a wholly uninspiring but functional pass, the Cobra Power 500W struggled in just about every test and did not pass all of these. When this unit was first pitched it was, and still is, labeled as being a "new" product. Unfortunately, the only thing new about this unit is the sticker (which is garish) on the unit. Otherwise, we are getting a recycled low end product who should not have been on the market 4 years ago let alone today. If Raidmax wants to improve its profile in the power supply market, it is really going to need to take a long look at its OEM partner and at some point realize that Raidmax, and Andyson, are screwing any chance of making headway by continuing to fall behind the curve with outdated products like this. This perception is especially acute when we see a poor HEC unit like the EVGA 500B running circles around this unit.

The Bottom Line

The Raidmax Cobra Power 500W, unfortunately, follows in the footsteps of the previous Raidmax RX-1000AE and even, perhaps, does worse. From start to finish, the only high point we could find with this unit today was the noise output, but even that gave us concerns as there is no good reason why it should be so quiet. Other than that, the Cobra Power 500W had poor voltage regulation, out of specification Transient Load Test results, mediocre DC output quality, poor component selection/build quality, and laughable efficiency. If the options were buy this unit or buy a hamster on a wheel to power your PC then you only have only one question. What do hamsters eat? In the grand scheme of things, there are good units, there are cheap units, and there are good cheap units. This power supply is none of those things and, at $58.92, this unit is 7 cents more expensive than the barely mediocre EVGA 500B while being a worse performing unit.

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Raidmax Cobra Power 500W

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