Rosewill Capstone 450W and 650W 80Plus Goldby Martin Kaffei on March 21, 2012 8:00 AM EST
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.