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E-power opened its California doors in 1990 as a small PSU supplier. Since that time they have grown and diversified their product line to include cases and accessories that range from case fans to server backplanes. Yet, they never abandoned their roots however, they are still best known for their power supplies.
Today we have E-power’s Thunder 550 watt PSU. Is this unit as touted; a quiet, efficient, “3 in 1” power supply? And, what exactly is “3 in 1”? Read on friend!
Contents and Features
The Thunder 550 watt retail box is feature packed. The unit ships with a color manual, mounting screws, a rainbow colored array of re-usable Velcro straps, a main power cord, and an EPUS cable (we will discuss that later). Additionally, the box informs us that this PSU is Crossfire and SLI ready. The 550 sports a black chrome (aka titanium black) finish. We have only seen a few power supplies with this finish and we have to say, it never gets old. It's a very hard finish to describe – and photograph. But, we figure the image below will give some idea of the shine on this unit.
This 550 watt unit follows a single 120mm fan design with honeycomb mesh exhaust grill. This design has nearly become de facto in modern PSUs, as the larger fan can cool at lower rpm (and less noise). That's the theory at least. The fan is clear plastic and back lit with a blue LED (actually, 4 LEDs). The LEDs are always on when the PSU fan is spinning (they do switch off in standby mode).
The clearly printed specification panel does double duty for E-Power and contains the specifications for both the Thunder 550 and 650 watt supplies. Our 550 watt unit has a pretty typical power distribution with 150 watt combined max on the 3.3V and 5V rails and a 420 watt combined max across the four 12V rails. Of course you can't get all that power at one time, the maximum wattage rating is 550 watts (go figure? Maybe that's why it's called a 550 watt PSU?). That's a good thing though and is typical of modern PSUs. It means, as an example, that if you need a bit more 12V power, and you are not fully loading the 3.3V and 5V rails, you can eek just a tad more out for the 12V side.
Cables, Connections, Dimensions
The Thunder 550 is not a modular unit, but E-Power did sleeve the eight wiring harnesses from tip to toe. The sleeving helps greatly when it comes to cable management, and we are glad to see E-power using it. Cable lengths, as can be seen below, are actually slightly longer than we typically see in PSUs - even high wattage ones. That's something to keep in mind if your system is in an unusually tall case or you like to really route cables around.
| Harness | Connectors and Lengths |
| 1 | ATX 24 or 20 pin mainboard connector. 21.5" long. |
| 2 | SATA power cable with connectors at 23” and 29”. |
| 3 | SATA power cable with connectors at 23” and 29”. |
| 4 | 4 pin peripheral power cable with connectors at 23” and 29" + FDD plug at 35". |
| 5 | 4 pin peripheral power cable with connectors at 23” and 29" + FDD plug at 35". |
| 6 | PCI-E 6 pin connector. 23" long |
| 7 | PCI-E 8 or 6 pin connector. 24" long |
| 8 | 12V 8 or 4 pin CPU power cable. 23” long. |
| Harness | Extender / Adapter Connectors and Lengths |
| 1 | EPUS cable with SATA and female USB power connector at 60" |
The unit doesn't come with any extenders or adapters, but this really shouldn't be a problem. The only conceivable connector that might be missing is an additional 8-pin PCI-E, and even that is unlikely as a dual 8-pin PCI-E system will need more than 550 watts (typically). The main cable is a 24/20 pin break away. This is good - a 550 watt PSU is what you might use to replace a failed PSU in a 20 pin legacy system. The PCI-E connectors are both blue so you won't get them confused with other connectors – specifically the 8-pin EPS connector. Speaking of, the EPS connector breaks into a 4-pin 12V connectors if need be. The 8-pin PCI-E also converts to a second 6-pin PCI-E for 6-pin multi-card systems.
And what about that EPUS cable? Glad you asked! This is a cable that hooks to the back of the PSU and can provide external SATA and USB power. The SATA cable is great if you have or intend to get an external SATA drive. The USB power cable is designed to supply power to non-data devices. That means you can use it to charge your cell phone or power that USB desk fan you are so proud of. The USB is also an always on socket, so you can charge your PDA while the system is off (Schweet!).
As far as dimensions go, the Thunder 550's are 6” deep x 5.9” wide x 3.4” tall. This makes the Thunder 550 just a tad (1/2 inch) too long to meet the ATX v2.3 guide requirements. E-power makes no claim on the box, in the manual, or on the unit that implies the Thunder 550 is fully ATX compliant. The honesty is refreshing and we doubt the long dimension will be an issue if installing the unit in a smaller ATX case, but a quick case measurement for fit is something we always advise.