Sunbeam Rheobus Extreme Fan Controller

Computers these days are not what they used to be in terms of heat output. Air cooling by fans is most common in today’s PCs, but while fans offer great cooling, they also come with the disadvantage of creating noise. The more air pushed through a system, the louder it tends to be. Most commonly the only fan in a PC with controllable speed is the CPU fan. This may help with the noise of the CPU fan, but it doesn’t quiet down all the rest of the fans in the machine. Due to this dilemma, fan controllers have become increasingly popular in the PC hobbyist community over the years. Thankfully we were able to get our hands on one of the best fan controllers currently, known as the Sunbeam Rheobus Extreme.

About Sunbeam:

Launched as a promising new company in the field in 2000, Sunbeam Company specialized in developing cold cathode fluorescent lamps (CCFL), and furthermore extended to manufacture various modding equipments. Throughout the years, Sunbeam has expanded their product coverage to provide pioneering and fancy computer application at all aspects, while focusing on, but not limiting to, cooling systems and computer cases. Sunbeam’s mission is to satisfy PC players all over the world who are tired of boring traditional computer impressions and longing for experiencing the excitements of revolutionary hardware designs.


  • Part Number(s): RHK-EX-SV (silver), RHK-EX-BA (black)
  • Dimensions: 148mm (W) x 42mm (H) x 82mm (D)
  • Maximum Output: 30W per channel
  • DC Input: +12V (4-pin Molex connector)
  • DC Output:
    • 0V – 12V DC (new model)
    • 4V – 12V DC (previous model)
  • 3-Pin Fan Connectors: 6
  • Fan RPM Knobs: 6
  • LED Lamps: 12 x blue LED 5V


  • Aluminum design, suitable for 5.25″ bay
  • Various brightness knob design; brightness controlled by knob
  • 6 fan adjustable function
  • Input 12V±10%, output 0-12V±10%, (max output 30 Watt each channel)

Package Contents:

  • Main Panel x 1
  • Power Connector x 1
  • RPM Signal Adapter x 2
  • 3-pin to 3-pin Extension x 2
  • 3-pin to Molex Adapter x 2

In-depth Look

First we’ll take a look at the design and the features of the black version of the Rheobus Extreme. Make note that this is the first version, as Sunbeam has recently released a revision that differs in a few areas. We will make note of the differences between the original and revised units throughout our review.

The moment you take the Rheobus Extreme out of the box, you know it’s meant for doing some serious work. All along the back of the unit can be seen large heatsinks to cool the unit when it’s under stress. Unfortunately, the unit we received had some heatsinks that wobbled a bit when pushed on. This is one of the quality issues mentioned earlier as these heatsinks are supposed to be soldered to the PCB. Some of the 3-pin fan connectors were crooked, but probably won’t have an adverse affect on performance. We also noticed that some of the controller knobs were set into the holes further than others which just seems to scream that the product was made cheaply.

Issues aside, one of the interesting features of the Rheobus Extreme is how the knobs light up. In addition, the brightness of the LED lights in the knobs are controlled by what position the knob is in. If it’s set to high, the knob is brightest, whereas when it’s set to low, the knob is the dimmest. This makes for a quick and easy way to tell what the positions are of the knobs even in a dark room.

Included with the fan controller is an assortment of connectors. As with all fan controllers, a main Molex power connector is included. Sunbeam has also decided to include two 3-pin extensions, two 3-pin to Molex connectors, and two of what Sunbeam calls “RPM signal to MB” adapters. The RPM signal adapters allow you to plug an extra end into a fan port on your motherboard so your motherboard will be able to pick up the RPM speeds from your fans. This can be especially helpful if you decide to plug your CPU fan into the Rheobus Extreme as it will allow software to read the speed of your CPU fan.

Performance & Testing

As with many of our reviews, we have tested the performance of this product. Unfortunately, the Rheobus Extreme did not seem to be able to provide very accurate voltages on all six channels. As you can see from the test results below, the voltages read from the channels on low ranged from 3.90V all the way up to 4.42V. This is quite a significant range and is definitely a concern of ours. On high the voltages were much more constant with the the voltages only ranging from 11.52V to 11.54V.

Revision note: We should note that the revised version of the Rheobus Extreme has rated voltages ranging from 0V to 12V which allows fans to be completely turned off at the lowest setting. We were unable to do any real-world tests as Sunbeam sent us the original version instead of the revised one.


  Low High
Channel 1 4.00V 11.52V
Channel 2 4.41V 11.53V
Channel 3 4.42V 11.54V
Channel 4 3.97V 11.53V
Channel 5 4.07V 11.52V
Channel 6 3.90V 11.53V


If you can get past the fact that the Rheobus Extreme has poor build quality, it is a great fan controller. During all of our tests, the only affect to actual performance was the somewhat inaccurate voltages at low setting. Other than these concerns of ours, the Sunbeam Rheobus Extreme holds up quite well under large amount of stress, especially when multiple fans are hooked up to a single channel.

At the moment, the availability of 6-channel fan controllers is somewhat limited. If you are really looking for a controller that has six channels, we think the Rheobus Extreme is a great choice. If you can deal with less than six channels, we’d recommend you consider another fan controller unless you are able to get the revised version.


  • Up to 30W per channel
  • More channels than you could possibly need
  • Large heatsinks for good heat dissipation
  • Generous assortment of connectors provided with unit


  • Poor build quality
  • LEDs are somewhat bright
One Comment
  1. TheDude
    July 27, 2008 | Reply

Add a Comment

Your email address will not be published. Required fields are marked *