With the Capstone series Rosewill provides very efficient power supplies in high-class cases. The ripple and noise voltage is low at all loads and performance is great. The total noise of the fan is satisfying as well, but a HDB fan would be better. Where things aren't so great is the number of Molex connectors (450W). The current market prices are influenced by what others traders are charging for similar product, and not surprisingly the cost is going to be quite a bit higher than lesser power supplies.

 Compared to the Seasonic X-Series X-560, Rosewill used the same converter type. The Capstone series combines the resonant circuit with an asynchronous half bridge and DC-to-DC converter on the secondary side. This is still one of the best circuit designs for an output power between 400W and 700W. Since the switching losses are reduced to a minimum, other components do not warm up as much. The result is that the Capstone series has low operating temperatures and a moderately controlled fan. The high-quality capacitors and EMI filtering are well developed, which should also be mentioned. However, the manufacturer SuperFlower continues to use no MOVs on the AC side, but we don't want to overdo things. Rosewill chose a good manufacturer.

As shown in our performance section, the Capstone 450W reaches 92% efficiency at 230VAC. Especially at low load the efficiency is noteworthy, because 80 Plus Gold requires good values only at 20%, 50%, and 100% loads​​. The +12V output is well regulated during overload and crossload. The other output voltages are close to the optimal values as well. The fan noise is suitable for an 80Plus Gold PSU. But it's also important to consider the type of noise a PSU generates. There are differences in how a ball bearing sounds and how a sleeve bearing/HDB sounds, with the last-named generally being preferred. For a high-end PSU Rosewill should use Sanyo Denki fans or a hydro dynamic bearing. Overall, though, the acoustic noise is not bad for a 450W power supply.

With six SATA and six Molex connectors, the 650W model is fairly well equipped while the 450W version should get more Molex plugs. In addition it might be better to have the PCIe connectors distributed to multiple cables, at the cost of cable clutter, but the wire cross-section helps make up for this. The 24-pin and the 12V harnesses are 55cm and 60cm long, so the power supply is suitable for most large PC cases. The cable sleeving is relatively opaque. A minor complaint is that, apart from the necessary items for installation and a user manual, nothing else is included in the package. The competition often offers a few extras, like some cable ties, and given the target market the lack of any extras is underwhelming.

The current prices for the CapStone series are $ 80-110. For an 80 Plus Gold power supply with this quality, the price is quite good. There are other options worth a look of course. For example, the Seasonic X-560 provides a better quality, using full modular cables and a better fan. The FSP Aurum CM 650W is also very cheap, but it's louder and more expensive than the Capstone 650W. Other alternatives like the be quiet! E9 series and the Cougar GX 700W models are significantly more expensive, but also a little quieter under load or equipped with a well-processed case.

Overall, we like the solutions Rosewill presented. The Capstone series is recommendable for all enthusiasts who want to get the highest efficiency. Minor flaws like the missing MOVs and the relatively cheap fan should be taken into account. After all the Capstone series gets our Silver Editors' Choice award for providing a very high efficiency.



View All Comments

  • Southernsharky - Wednesday, March 21, 2012 - link

    Are we now trying to con the public into believing that they need a high end power supply to make their system work?

    I've been using the cheapest PWs I can find in my systems since oh... 1985 and I have had a few fail, but over the course of 25 years, I can only think of maybe 3 that failed. And there is no guarantee the same thing wouldn't have happened with the expensive models.

    As for energy efficiency...... its over rated. Unless the efficiency saves me more money than what I spent on being efficient then its not relevant. I'm guessing the difference between an efficient card and an inefficient card is right around .50 cents to a dollar a month. So I'd have to run 80-120 months to realize a difference.
  • Dusk Star - Wednesday, March 21, 2012 - link

    In previous reviews, they seem to highlight the fluctuations in the power output- critical for a stable overclock. And this is largely a site for tech-savvy people; not the type to be as easily conned. I have also heard too many "horror stories" of people having their PSU fail and burn out a $300 graphics card on their way out. My point is, there may be more point to these reviews than to get people to buy more than they need. Reply
  • Martin Kaffei - Wednesday, March 21, 2012 - link

    One problem is that most cheap PSUs have no real power rating. Usually you don't get any problems but some users overestimate the possible output power and use $10 PSUs in a high-end PC. That's what Dusk Star mentioned in other words.

    Basically cheap PSUs have advantages (simple circuit designs) and some disadvantages (low efficiency). But peak power rating is unacceptable for me. In addition we should keep in mind that electricity costs will rise.
  • mpschan - Wednesday, March 21, 2012 - link

    Dusk Star is right.

    I had a half-way decent power supply blow out a motherboard and a graphics card. $400 down the drain.

    It taught me a valuable lesson: spend more money on your power supply so it doesn't destroy hundreds of dollars in other equipment.

    I love seeing reviews like this. Keep up the good work!
  • jabber - Friday, March 23, 2012 - link

    It always makes me laugh when I read in the Power Supply section of forums someone comes on and says -

    I need to run a i3/4GB/2xHDD PC with a $80 GPU. What level of PSU do I need?"

    Then all the experts start pulling figures out of their backsides and start saying "Oh you need a 800W minimum!"

    Fact is 85% of even the most committed enthusiasts PCs probably would run just fine with a good quality 500W.
  • michaelheath - Wednesday, March 21, 2012 - link

    "Are we now trying to con the public into believing that they need a high end power supply to make their system work?"

    I would imagine the enthusiast community is capable of independent thinking, and they read more than one review before coming to a purchasing decision.

    "I've been using the cheapest [PSUs] I can find in my systems since oh... 1985 and ... over the course of 25 years, I can only think of maybe 3 that failed."

    That's 3 more than the number that have failed on me in nearly the same time period.

    "And there is no guarantee the same thing wouldn't have happened with the expensive models."

    There's no guarantee that a $100k Mercedes Benz won't break down after 100 miles of driving. What's your point?

    "As for energy efficiency...... its over rated. Unless the efficiency saves me more money than what I spent on being efficient then its not relevant."

    How I read your statements: Never mind the cumulative difference in power consumption if everyone ran a ≥85% efficient power supply, including being able to reduce the resources required to power millions of computers in North America alone. Forget the fact that a quality power supply would more than likely outlast a cheap PSU two-fold, thus reducing electronic waste. What matters is I don't feel like I'm saving money.

    I have over 200 systems deployed in my work environment, all with ≥85% efficient power supplies. I assure you, the people who approve my spending would much rather see a smaller electric bill and lower repair/replacement rates (which, coincidentally, occurred after I started using higher-efficiency-yet-lower-wattage PSUs) than the opposite if I saved a few bucks per machine and didn't care about what PSU I used. They're especially grateful during the Summer, when an inefficient PSU produces more heat and becomes even less efficient to maintain stable power output... which doesn't happen with a good, quality, efficient, yet slightly more expensive unit.
  • anactoraaron - Wednesday, March 21, 2012 - link

    If you are using the cheapest 'PWs' you should measure the power draw under those PWs. My rig with an 'el cheapo' used to draw 470 watts under load and now with an 80 plus PW it draws 285 watts. That's about 200 watts difference. Efficiency isn't exactly over rated. FWIW, my rig used to draw about 30 watts when it was off with the 'el cheapo' and now only draws 6 watts when powered down. So unless you are constantly unplugging your rig or you are switching the PW off energy efficiency comes into play there as well. Reply
  • JarredWalton - Wednesday, March 21, 2012 - link

    His suggestion that a "cheapest PW" would only use $0.50 more per month is also way off. $0.50 per month works out to a difference of 7W for 24/7 usage. Even if we take a lower end system that idles at 60W output from the PSU, that would use 86W with a 70% efficient PSU or 71W with an 85% efficient PSU -- a difference of 15W or around $1.00 per month. If it were a more reasonable system that used an average power of closer to 120W then that doubles to $2.00. (That's at my price of $0.10 per kWh, which is lower than the national average of $0.16 per kWh.)

    Of course, even 70% efficiency is more than the "cheapest" power supplies would offer. Let's say you get a real dud and it's 50-60% efficient (which is likely if you buy a $25 PSU). Now you're looking at a 60W system load drawing 100-120W vs. 71W, or a moderate load of 120W that would pull 200-240W vs. 141W. That would be a difference $2 to $3.50 per month for a low power system, or $4 to $7 per month for a moderate system. Considering you would be paying about $25 more in power per year as a minimum, or as much as $84 per year for a moderate system, you'd more than pay for an upgrade to a better PSU in one year.
  • adece - Wednesday, March 21, 2012 - link

    I'll take your word on "the cheapest PSUs" and link you to an article about it:

    I'm pretty sure AnandTech did something similar but I can't find the article.
  • adece - Wednesday, March 21, 2012 - link

    Found it:

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