Crystalfontz CFA-635

Overall Score

Article by: Drew Duncan

Photography by: Drew Duncan


Crystalfontz CFA-635 review

Review Type: Our pocket (not 3rd party sponsored, supported or funded.)


Setup: 9/10 (10=easy)

Difficulty to configure: 7/10 (10=hard)

Ease of use: 9/10 (10=easy)

Learning Curve: Roughly 2 hours for an experienced computer user.

Setup Time: Hardware -about 1 hour | Software -about 3-4 hours depending on how resourceful you are, and what your needs are.


We review the ultimate in computer mods, the CFA-635 and decide whether or not it is worth its weight in gold.



XCPUS quick Crystalfontz information:

  • International shipping.
  • USB and Serial connection variants.
  • Multiple colors and Backlights to choose from.
  • 9.51 / 10 @ (
  • Fully programmable modules using C source code.
  • Liquid Cooling interface ability. (page 4)
  • Multi core Processor Compatible (Monitors up to 4 cores).
  • Linux and Windows compatible.
  • CrystalControl Supports Windows 95/98/Me, NT4/2000/XP
  • CrystalControl2 does not support Windows 95/98/Me since it is ran as an NT service.
  • CrystalControl2 works with Vista although it’s still under works, the device works fine in Vista. Most recent Vista driver. (Patch notes included)
  • Designed, Manufactured and shipped in the USA for complete quality control.
  • Manufacturing is ISO 900x certified.
  • Does not support multiple languages.


When most people decide to mod their own computer they decide to get a case with a clear side panel and throw in a cold cathode. The slightly more mod savvy will take it a step further by organizing all the cables with zip ties, and maybe even opt for LED or UV reactive fans and purchase a 5.25" fan controller. Then there are serious hardware people always looking for that serious eye-candy that gives them more functionality for their computer and gives them the ability to manage or even monitor everything. For the most serious of hardware aficionados there is a company located in Spokane, Washington that makes high-quality LCD modules for your computer that can do absolutely everything but massage your shoulders.


Crystalfontz has been around for quite some time and they know what the hardware geeks want and they give it to us in a very appealing fashion. They have many USB solutions available to accommodate anything from 3.5" floppy drive bays to 5.25" CDROM bays, and even a rugged housed external LCD which can rest on your desk and easily be removed and then plugged into your laptop, a friends computer or even your work computer; perfect for lan party goers.


Let’s see what we are dealing with here…

Today we will be taking a very close look at the CFA-635 USB LCD module along with the UBER S.C.A.B. (System Cooling Accessory Board with the accessory cables). The S.C.A.B. allows you to monitor the temperature of up to 32 devices inside of your computer by daisy chaining the temperature probes together. The probes are capable of measuring the temperature of the device they are attached to within a 0.5 deg C absolute accuracy which makes monitoring HDD, NB, SB, PCB and even your PSU temperatures a breeze. The S.C.A.B. also allows you to monitor as well as adjust the speed of up to four (4) fans. You can even specify at what temperatures you would like the fan speed to rise at and to what RPM and you can do that independently for each channel.

The CFA-635 also has 4 built in LEDs that you can individually setup pretty easily once you figure it all out. When you install the Crystalfontz program CrystalControl2, it gathers a list a of a few properties such as your CPUid (or on dual cores both id’s, or even Quad cores with the 4 id’s) so that you can set the LEDs to change colors (any color in the spectrum between Green and Red) depending on how hard your processor is working across single, dual, or even quad core systems. If you would like to, you can even setup the LCDs to display network bandwidth or even HDD usage/space. The CFA-635 truely is an amazing piece of technology that let’s you, the user, decide what you do and don’t want.

In the following picture you will see the CPU running Prime 95.

I have the top two (2) LEDs displaying Core 1 usage, and the bottom two (2) displaying Core 2 usage on a Core 2 Duo e3110.


There are 3 different colors that transition smoothly; Green, Orange, and Red.

The bottom LED represents 50% workload on Core #2 (0-50%), while the second to the bottom LCD represents the other 50% of Core #2 (50-100%). When the bottom LED is SOLID RED it is at least a 50% workload. Perhaps showing you another picture will give you a better understanding of how this works.

In the following picture you will see the CPU running Windows XP SP3.


Let’s have a closer look at the unit itself…

The Product

Taken directly from

Crystalfontz 635 features

  • LED backlit STN 20×4 LCD
  • Integrated LED backlit 6-button translucent silicon keypad with screened legend

  • Four bi-color (red + green) LEDs. The LEDs’ brightness can controlled by the host software, which allows mixing the LEDs to produce other colors (yellow and orange)

  • Two color options:
  • Fully decoded keypad: any key combination is valid and unique

  • LCD characters are contiguous in both X and Y directions to allow the host software to display “gapless” bar graphs in horizontal or vertical directions

  • USB interface for both power and data (115200 baud equivalent throughput)

  • Robust packet based communications protocol with 16-bit CRC

  • Compact size: fits in a 1U rack mount case (37mm overall height)

  • ATX power supply control functionality allows the buttons on the CFA-635 to replace the “power” and “reset” buttons on your system, simplifying your front panel design

  • Built-in factory re-programmable microcontroller

  • 5.25" half-height drive-bay mounting bracket available (optional)

  • Non-volatile memory capability (“EEPROM”):
  • Customizable firmware and configurable hardware can be modified at the factory to add specific features for your system needs. Minimum order and tooling fee may apply for custom firmware:
  • 5.25" half-height drive-bay mounting bracket available (optional)
  • Printable 1:1 Acrobat template: 635 one_to_one.pdf
  • Mechanical Characteristics::
    • 142.0(W) mm x 37.0(H) mm PCB Outline
    • 82.95(W) mm x 27.5(H) mm Viewing Area
    • 77.95(W) mm x 22.35(H )mm Active Area
    • 3.85(W) mm x 5.55(H) mm Character Size
    • Thickness:

      Without Keypad or Connectors: 10.6 mm

      With Keypad, without Connectors: 14.4 mm

      Without Keypad, with Connectors: 15.5 mm

      With Keypad, with Connectors: 19.3 mm
    • Keystroke Travel (approximate): 2.4 mm


SCAB features

  • Allows the CFA-631 and CFA-635 to perform the same fan and temperature cooling functions that are available on the CFA-633
    • Four fan connectors with RPM monitoring and variable PWM fan power control
    • Temperature Monitoring: up to 32 channels at up to 0.5 deg C absolute accuracy
  • The CFA-633’s four GPIO lines are duplicated on the SCAB, which allow
    • ATX power supply control functionality allows the buttons on the CFA-631 or CFA-635 to replace the "power" and "reset" buttons on your system
    • Hardware watchdog can reset host on host software failure
    • Advanced digital GPIO control with PWM output
  • Full control of the cooling features using 631_WinTest for the CFA-631 and 635_WinTest for the CFA-635
  • Printable 1:1 Acrobat template: SCAB_one_to_one.pdf
  • "UBERSCAB" includes 4 temperature cables (WRDOW17), 4 fan extension cables (WRFANX01), one 3.5" CFA-631/635 to SCAB connector cable (WREXTY19), and one 16" CFA-631/635 to SCAB connector cable (WREXTY15). 


CFA-635 mounting bracket

  • Mounts a backlit 635 display in a single PC "CDROM" size 5 1/4" drive bay.
  • Precision formed rigid metal bracket


Anything else…

S.C.A.B. Accessories

  • 4 extended fan cables
  • 4 temperature probes
  • 1 internal USB cable
  • 1 external USB cable

Here are some pictures of the temperature probe.



Not thin enough to be used between the processor and a heatsink, but perfect for monitoring your PSU, HDD(s), RAM, NB, SB, VRM… you name it.


Here is how they daisy chain together, keep in mind that you can daisy chain not just 4, but up to 32 temperature probes.



Additional aftermarket accessories

If your system is liquid-cooled, your still in great shape. With the purchase of a Swissflow flow meter SF 800 or a Flow Meter PRO Rev3.6
you can digitally monitor the flowrate of your liquid. The S.C.A.B is already capable of monitoring the speeds of your RAD fans and it’s capable of monitoring the temp of the liquid at up to 4 places in your pipeline.


The Package that it all came in

Upon arrival I was rather surprised to find a small boring white cardboard box about the size of O.E.M. CD drive box. It was rather unimpressive and caught my attention immediately in a rather negative way. It was taped shut with packing tape and had a label slapped in the center showing the companies name and address; the kind you would typically see at the top left hand corner of your envelope mail as a an address label. I know Crystalfontz is a rather small company but product packaging is all about impressing your customer and getting them amped about the product on the inside. Needless to say, I already knew what was inside so I wasn’t too terribly concerned.

Upon opening the package everything was very neatly organized, bubble-wrapped, padded, and individually sealed. I would say that they were aiming for a very efficient yet minimalistic approach.There was no software or instructions on how to properly configure the product. Other reviews across the internet have also noted that they did not received any instructions. So you will need to get the instructions online as well as the software.


So what can this thing do for me?

Besides just monitoring temperatures and fan speeds, the unit is fully capable of doing just about anything you can imagine.

Here are just a few really quick examples that don’t even begin to scratch the surface of what the CFA-635 is truly capable of.

  • Custom Boot screen
  • .GIF image display
  • Date/Time
  • Cpu speed
  • Individual Cpu Core temperatures (dual core and single)
  • CPU usage across a single (1 bar) or both cores (2 seperate bars)
  • GPU Clock speed
  • GPU Mem Frequency
  • GPU temp
  • GPU PCB temp
  • FPS
  • Memory Usage
  • Winamp info and visual effects.
  • Newsfeeds (BBC, Slashdot, [H], etc etc)
  • Ping different servers (Microsoft, Google, etc etc)
  • IP information
  • Set fan speeds to a predetermined speed when a probe reaches a certain temperature.

So what about that installation and software?…


The install is rather simple, just plug in the cords that you would like to utilize in to the S.C.A.B.




Plug the USB cable into your motherboard, or use the external USB cable.


Then install the software required to run the program.


Run the downloadable 635_WinTest to make sure everything is working


The test system

Asus Rampage Formula

Intel e3110@4.25 and 4.5ghz

Thermalright Ultra-120 Extreme

Sapphire 4870 512mb

G.Skill PC2-8500 8gigs @ 1000mhz

Sony Dru-820A

Seagate 7200.10

GameXstream 850


Let’s get to it…

Any rFactor fans?



Look at the possibilities!



For those of you using Vista with only 2gb, don’t worry the memory footprint is pretty low for all that it does.


So what does it do for me?…


My Machine during system boot-up.


My Machine shortly after system boot-up.


Pinging my favorite website at timed intervals. (3 seconds is good enough for me)


Listening to some music through Winamp. Windows Media Player will do the same thing as well.


Memory usage.


Speedfan monitoring my temperatures at timed intervals. (3 seconds is good enough for me)


HDD space available accross 2 HDD’s (4 partitions).





and the Conclusion?…



Crystalfontz has delivered a terrific product for not only the modding community, but the hardware enthusiasts among us. This device has truely amazed me over the last year that I have had it. With each patch comes new content, improved features and greater interaction with 3rd party programs. Some of the 3rd party plug-ins are available for the community to use as a guilde to write their own plug-ins, jc634 is one such major contributer. The forum, although not extremely active, has Admins that will respond to your post within 2 hours, and call on the help of other admins as seen here.

Great Articles on the Forums:


  • Great Expanability.
  • Easy to use Software.
  • S.C.A.B. is a welcome addition
  • Solidly constructed Hardware.
  • Great price for all that this unit is capable of.
  • The Forums are extremely helpful.
  • Bright display that is easy to read (Brightness and Contrast can be user adjusted)
  • Makes a computer look "Complete"
  • Great for those wanting to monitor temps and flowrates of WC systems.
  • Fully programmable. (read page 22)
  • Overlay available in Brushed black aluminum, Brushed Silver aluminum, Beige Plastic and Black Plastic.


  • No included instructions, but not really needed.
  • The CrystalControl2 software can be difficult to find the first time.
  • The online manual can be difficult to find the first time.
  • Having only 4 fan headers may be an issue to some.



CFA-635 w/ UBER S.C.A.B. $130

Discuss this review here.



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