Introduction

We would like to thank Rosewill for supplying the review sample.

Rosewill is the house brand of Newegg, probably the largest online store worldwide, so they feature a pretty rich catalog of products which includes even Power Supply Units. Usually in-house brands, at least as far as PSUs are concerned, are considered of low quality and performance, but apparently Rosewill is an exception since they co-operate closely with Super Flower, which is one of the best OEMs.

The new modular Capstone units are available in four capacities: 450W, 550W, 650W and 750W. All are 80 Plus Gold certified, ErP Lot 6 2010 (or EuP) ready, feature a silent double ball bearings 140mm fan and also use exclusively Japanese capacitors. Moreover they have a single +12V rail which can deliver almost the full power of the corresponding unit in all cases, so even the smallest one, the 450W model, can output 37A at +12V, a power level that will suffice for a mainstream system.

In today's review we will fully evaluate the strongest modular Capstone which has 750W capacity and a 62A +12V rail. This unit can support up to two high-end VGAs with its four PCIe connectors and it is also equipped with two EPS connectors so it can feed server mainboards with more than one processor. Finally, Rosewill provides a hefty five year warranty along with all Modular Capstones, so the future buyer will enjoy a long peace of mind.

Specifications

Efficiency is 80 Plus Gold and the operating temperature range is pretty large since this unit can deliver its full continuous power up to 50°C. Normally in a PC chassis with good airflow the ambient won't exceed 35°C but especially PSUs require resilience to high operating temperatures (>40°C), which usually translates to higher reliability and better quality. When it comes to electronic components (e.g. capacitors) as their temperature rating increases, their quality and lifespan follows. Unfortunately components with higher temperature rating cost more and this is clearly seen in caps where the 105°C ones are more expensive than the corresponding with 85°C rating.
Although the PSU has 750W capacity with almost all of it being available at +12V alone, the manufacturer claims that it is equipped with OCP, a protection that is practically useless in a medium-high capacity single rail PSU. Well we will check on this once we take the unit fully apart. Regarding the rest of the characteristics, at a glance the fan has the usual 140mm diameter, the unit's dimensions are compact for its capacity and the warranty is set at five years. Finally the price looks a little stiff for a house brand PSU but do not forget that this unit has nothing to do with usual house brand products since it is made by one of the best PSU OEMs, Super Flower.


The minor rails are strong enough with 120W max combined power. After all, modern systems don't draw much power out of these two rails. On the contrary, the +12V rail is heavily utilized nowadays so in this case the manufacturer granted it with 62A capacity. Finally the 5VSB have sufficient power for the category that this unit belongs to.

Cables & Connectors, Power Distribution

The PSU has three native cables including the main ATX connector and the two EPS ones. In our opinion the second EPS connector should be modular since most users will not utilize it. Overall the unit has a sufficient number of connectors for its capacity and the good thing is that both EPS along with the four PCIe connectors are available at the same time. Also all cables are long enough and the distance among connectors is the right one according to the ATX spec. Finally all wires have 18AWG size which is the recommended one. In a 750W capacity PSU it isn't necessary to utilize thicker wires, something that will have a negative impact on their flexibility, since current will not be high enough to cause significant voltage drops.

Since this PSU features a single +12V rail we do not have anything to comment about its power distribution.

Packaging

The small packaging has a handle on its top, to help you move it around. The overall design used isn't so fancy but still looks good to the eye. Nearly half of the box's front side real estate is occupied by a quarter shot photo of the PSU. The fan grill center looks a bit like something is missing, a badge would have helped here. Further to the left we meet the series and the capacity descriptions and below them there are three badges for the Gold efficiency, the five year warranty and the modular design (actually semi-modular). On the rear side of the box we find a large table showing the cable configuration of all modular Capstone units and right next to it there are four smaller tables describing the power specifications of the same units.