

The Capstone 550 Watt power supply is 80 PLUS Gold certified and delivers up to 90% efficient performance under typical loads. This high form of efficiency saves energy, reduces heat in your system, decreases fan noise and prolongs the PSU’s life span so you can maximize your gaming activity.

Capstone PSUs are backed by 5 years of warranty. Your power supply unit will operate according to its technical specifications within intended operating environments for the length of the warranty period.

Capstone PSUs have successfully passed safety and compliance tests from CE, FCC, TUV, and cTUVus.

With Auto Fan Speed Control, the power supply’s 135mm fan turns slowly at low temperatures, reducing power consumption and fan noise to near silence. When temperatures increase, fan speed will also increase. This decreases the odds of over-heating, extends the fan’s life span and reduces energy consumption.
A semi-modular PSU design comes with only the essential cables pre-attached. This allows for some customization of additional cables, plus reduced clutter and better airflow compared to non-modular PSUs within your computer case or system.


STYLE | CONNECTOR TYPE | CAPSTONE 550M | CAPSTONE 650M | CAPSTONE 750M | CAPSTONE 850M |
![]() |
20+4 Pin | x1, 23.64 in | x1, 23.64 in | x1, 23.64 in | x1, 23.64 in |
![]() |
8 & 4+4 Pin - EPS | - | - | x1, 25.61, 35.4 in | x1, 25.61, 35.4 in |
![]() |
4+4 Pin - EPS | x1, 25.61 in | x1, 25.61 in | x1, 25.61 in | - |
![]() |
Split PCI-E | x1, 23.6, 29.5 in | x2, 23.6, 29.5 in | x2, 23.6, 29.5 in | x2, 23.6, 29.5 in |
![]() |
SATA + 1 Molex | x2, 19.7(s), 25.6(s), 31.5(s), 37.4(m) in | x2, 19.7(s), 25.6(s), 31.5(s), 37.4(m) in x1, 19.7(s), 25.6(s), 31.5(m) in |
x2, 19.7(s), 25.6(s), 31.5(s), 37.4(m) in x1, 19.7(s), 25.6(s), 31.5(m) in |
x3, 19.7(s), 25.6(s), 31.5(s), 37.4(m) in |
![]() |
Molex + 4 Pin Floppy | x1, 19.7(m), 25.6(m), 31.5(m), 37.4(f) in | x1, 19.7(m), 25.6(m), 31.5(f) in | x1, 19.7(m), 25.6(m), 31.5(f) in | - |
![]() |
SATA + Molex + Floppy | - | - | - | x1, 19.7(s), 25.6(m), 31.5(m), 37.4(f) in |
*LEGEND: (in) - inches, (m) - Molex Connector, (s) - SATA Connector, (f) - Floppy Connector
Pros: High quality internals Excellent Warranty Quiet Operation Modular High Efficiency
Cons: A bit expensive at MSRP Plain design
Overall Review: I purchased the Capstone 550W to replace my XFX 650W that had it's fan die. The Rosewill was on sale for $49/AR so the price was right and the high efficiency is desirable because I run it in my gaming HTPC 24/7. First of all, this PSU is pretty basic in presentation. For me this is not a big deal, others potentially more so. The modular cables have decent length, easily reaching all my components in my Silverstone GD04B HTPC case. It is powering a lightly overclocked i5-2500k , Sapphire HD 7950 (1100/1700) , 240GB SSD, 5 case fans, CPU cooler and a 2TB Seagate HDD. Having tested various stress tests, including media encoding and gaming, the Capstone has had no issues and the fan is quiet. Downright silent compared to my case fans which have a light audible hum. Without testing how much power I am pulling from the wall, I do not have time to validate it's efficiency, but according to various professional reviews it easily hits Gold standards and uses quality Superflower internals. Realistically I am only pulling 350W max at any given time, so the PSU is not getting taxed that hard. Overall I am happy with the performance thus far and am pleased that the PSU has a lengthy 7 year warranty.