CrystalFontz CFA-635

by Matthew Harris on April 11, 2006 in Peripherals

With the cornucopia of fan controllers and temperature monitors on the market today it’s not very often that you run across one that brings a whole lot more to the table. Today we’re taking a look at one that brings more than just fan speed control and simple temp reporting.


In parting a pair of shots of how the CFA-635 integrates into my rig in the dark and in the light. I went with black over silver since my ODDs are black along with my media reader/front panel so the black is in keeping with that look and the brushed aluminum is a nice segue into the aluminum of the case.

Now on to the good, the bad and the not so pretty. The CFA-635 is a very nice unit that comes damned close to being a panacea for fan control and system monitoring. The use of PWM for the fan control is a mixed bag though, it allows for lower fan speeds due to the pulses of full voltage rather than incremental voltage but as I stated earlier, it doesn’t play well with high torque devices. It supplies plenty of power (18W continuously with 60W peak per header) for larger fans but the pulses can wreak havoc with them and make for louder than normal sound from them. The temp sensors are pretty accurate, I attached them to a heat source that I checked with a Ray-Tek mini IR gun and the temps they reported were within .2C of what the Ray-Tek reported so for your temp needs you can be assured that you’re getting pretty true readings from them.

Sadly they’re huge by temp sensor standards. They’re easily 10-15 times the size of the mini diodes provided with many temp reporting devices. They’re also 5 times the size of the larger beads that you find with the older Digidoc. This makes placement a ticklish procedure. The display unit is surprisingly legible considering that the other 4 X 20 unit Crystalfontz offers is a dual bay unit. They’ve managed to shrink the size down but not sacrifice any of the readability.


  • Easily setup
  • Legible display with great off axis readability
  • Great expandability (up to 32 sensors, can power up ATX systems with an optional adaptor)
  • Very, very flexible setup, fully configurable fan speed control
  • Dozens of pre-configured screens
  • Very attractive

  • No user configured screens without writing them
  • Huge temp sensors
  • PWM means "Big" fans have to either run at high RPM or be off to not chatter
  • Side LED’s are not implemented yet in software (This is why I never mentioned them)
  • No hardcopy included with the unit
  • No software included, it must be downloaded and is difficult to find

The cons are as long a list as the pros and annoying in that they prevent this unit from being perfect instead of damned near perfect but that said it still is nearly perfect. The cons are mostly minor and I’m certain that a couple will be rectified in the near future (At least I hope so) so based on that I’m awarding the Crystalfontz DB635AK-TMF-KU3 an 8/10 and our coveted editors choice award. The Crystalfontz DB635AK-TMF-KU3 is available directly from Crystalfontz website and will run you $135 and change as configured here. Go check them out.

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