The Corsair Vengeance K70 and Linux

⌚ July 1, 2014The keyboard, mouse, and monitor are among the most important hardware components for a computer system because they are what we interact with.

Struggles and frustrations with any of these devices make computer usage a chore, so why not improve these items to make computing more fun?

One quality keyboard is the Corsair Vengeance K70. It features mechanical keys, backlighting, excellent tactile response for improved typing, extra WASD keys for gaming, and some of the best multimedia keys I have ever used on a keyboard.

I had the chance to use this keyboard, and I am impressed! There are a few minor issues involving Linux, but overall, I am pleased with this keyboard. Here are my thoughts.

The Keyboard

Let’s have a look at the hardware. The keyboard is shipped in a quality box touting its features.

Packaging includes the keyboard, a wrist rest, a key-puller, paper guides, and extra keys than can replace the WASD and 1-6 keys.

Mechanical Switches

The primary reason for obtaining the K70 keyboard is for the type of switches used for the keys. This model uses what are called Cherry MX Red switches. Mechanical switches are supposed to be durable and use actual switches rather than simple contact pressing found in lower-quality keyboards.

There are two other types of switches available, Cherry MX Blue and Cherry MX Brown, and they offer different styles of tactile feedback, such as clicking, when keys are pressed.

Keep in mind that Cherry MX Red does not refer to the backlight color of the keyboard. This model happens to have the red lighting. A keyboard with blue backlighting can still use Cherry MX Red switches, so pay attention to the fine print in the keyboard’s description.

Mechanical switches make these keys instantly responsive and “spring back” as fast as your fingers fly, so if you are the kind who likes to go “tat-tat-tat-tat-tat” with keys in rapid succession, then you have met your match. Perfect for the fast typist!

The surface of the keys themselves have a semi-soft, matte feel.

Sound

This keyboard is much quieter than I expected. The Cherry MX Red key presses feel smooth to the touch. There is no “clicking” sound heard when keys are pressed. For those who are familiar with the “clicky” nature of micro-switches, such as those used for mouse buttons, this keyboard sounds nothing like that.

However, there is a distinct plastic-on-plastic “clack” sound made when a key “bottoms out.” This is caused when the inside of the key presses against the base of the plastic switch that it rests upon. It can be quite loud, but there is a way to dampen the effect using rubber o-rings (discussed later).

Keyboard Cable

The keyboard cable is much thicker because it contains two separate USB 2.0 cords inside. One is for the keyboard itself, and the other is for a dedicated USB port located on the back of the keyboard.

Back of K70 showing the USB port, BIOS switch, and the thick cable. The cable feels smooth and at is easily flexed. Nothing stiff or hard.

This results in two USB plugs: one for the keyboard, and the other for the USB port.

The K70 has two USB plugs. The plug on the left is for keyboard (Required), and the plug on the right is for the USB port (Optional).

The keyboard plug is a requirement in order to use the keyboard, but it will not power the USB port. For that, the USB plug must also be connected to the computer. The K70 will work fine with only the keyboard plug connected.

There is plenty of flexible cable, and it has a smooth, braided texture that is as much fun to stroke as a soft, cuddly kitten.

USB Port

Located on the back of the keyboard is a USB 2.0 switch. It does not support USB 3.0. Already tried that. The primary purpose of this port seems to be for connecting an extra USB peripheral, such as a mouse or touch tablet.

It works! While the idea is not new, the capability of daisy-chaining a USB mouse with the keyboard helps keep the input devices tidy and makes it easier to swap mice without reaching behind the system unit, but this is a matter of personal taste. The K70’s USB plug must be connected in order for the USB port to function.

Here, we see the Cyborg R.A.T.7 connected to the USB port located on the Vengeance K70. The black/red scheme of the R.A.T.7 matches the K70 well.

BIOS Mode Switch

Also on the back of the keyboard is a BIOS mode switch that is supposed to enhance compatible with various BIOSes. Personally, I set the switch to 1 and leave it be for both Linux and Windows. There are issues with Linux depending upon where this switch is set (discussed later).

In general, if the keyboard has compatibility issues with a certain motherboard, try another BIOS mode by setting the switch on the back.

Multimedia Keys

Yes! Unobtrusive, user-friendly multimedia keys! The brilliant aspect of the K70 is that it knows that it is a keyboard and does not try to include a worthless set of extra buttons that increase visual keyboard clutter.

The few extra keys provided are functional and used frequently. Stop,Back, Play/Pause, Forward, Mute, and a volume control are provided, and they work with perfectly Linux Mint 17 and Xubuntu 14.04. No Linux configuration necessary. I controlled VLC, Audacious, and Clementine (individually) with ease using these keys even when the programs were not in focus.

Since there is no plastic encasing, the row of four multimedia keys immediately above the number keys feel deeper to press. It works well to avoid accidental presses, by it takes some adjustment.

Volume Control

Who would have thought that the volume control on a keyboard warranted its own discussion? The K70 volume control is a metal, horizontal scroll bar that is fun to use! This is easily the smoothest-scrolling volume control I have ever used on a keyboard. It adjusts the volume perfectly in Linux, and it feels substantial yet accurate. The mute button is located conveniently to its left.

Backlight Keys

The keys illuminate! Red, for this version, and there are fours steps: Off, low, medium, and high.

The lighting is similar to the type of lighting used on a string of LED Christmas lights. If you are the type of person who notices the slight LED flicker from LED Christmas lights when you move your eyes, then you will see the same effect here. Lighting is not steady as seen on other keyboards using different illumination techniques. This is a minor point that some might not notice, but I definitely notice it when looking from the keyboard to the monitor in quick succession.

Individual Key Lighting

Each key has its own LED. This means you can create custom illumination patterns of keys that will light up when you press the backlight program button. All other keys remain unlit. For example, if you are playing a game in a dark room, you can illuminate only the needed keys. If you are watching a video file, only the control keys need be illuminated for easy access.

There is also a flash key effect that illuminates keys as you type. Release a key and the key becomes unlit again. It adds a visual feedback element during typing. Fun to watch. To enable it, hold the left control key and press the backlight program key. This feature is not documented with the included paper.

Windows Key Disable

The third button between the backlight buttons and the keyboard LEDs disables both Windows keys, which are called the Super keys in Linux. As long as the BIOS mode switch is not set to BIOS mode, pressing this button will make the Windows/Super keys ineffective.

Backlight control buttons. The three buttons from left to right: Backlight Program Key, Backlight Brightness Key, Windows Disable Key.

This is an invaluable feature that should be included on every keyboard. Suppose that you are playing a full-screen game in Windows and you accidentally press the Windows key by accident during an intense gaming moment. The game will pause/minimize/whatever and you will be returned to the Windows desktop. What an aggravation. Toggling this button disables the Windows key to prevent this scenario from happening.

In Linux, this does not seem to be too useful, but the option is present.

Plastic/Aluminum Build

The K70 touts an aluminum finish. Combined with the word “mechanical,” you might think that this is a heavy, metal keyboard.

It is not.

It is lightweight and made almost entirely out of plastic. The keys are plastic. The case is plastic. The wrist rest is plastic. The keyboard has a hollow, plastic feel and produces a slight plastic echo inside as keys are pressed. I was expecting more of a solid construction, but no.

However, the top consists of black, brushed aluminum, which is metal. It lends an attractive finish to an already fine keyboard.

The only obvious aluminum is the black, brushed aluminum plate covering the entire top of the keyboard. This corner view shows the thickness of the aluminum.

Easy to Clean

There is no plastic mold surrounding the keys, so the keys feel exposed. This is great because it makes it easy to remove keys to perform cleaning.

The keys pull out with ease. The included key puller (seen affixed to the 6 key) makes the task simple. Each key has its own LED (seen as the clear LED above each red switch).

On other keyboards, food particles, hair, dirt, dead skin, slobber, and a host of other nasty stuff gets trapped between keys deep inside the keyboard where it encrusts and putrefies over time. Only a thorough dissection will tide the stem of bacteria growth, but cleaning is not easy to perform on traditional keyboards.

But on the K70, it is a simple task. Just remove the keys with the included key-puller! The keys were designed to be removed, so cleaning is quick and easy.

Removable Keys

The plastic O-tool seen in the picture facilitates key removal. Simply snap it over a key and pull. The keys pulls off of the switch quickly and easily without any damage or scratching to the keys or keyboard.

The K70 package includes ten extra red keys for gaming, and they replace the WASD 1-6 keys. The slight contour and slight rigid texture make these keys feel different from the regular keys so you can feel them without looking at the keyboard.

Horizontally, they create and angled bowing to match the shape of your fingers. You might think that this would interfere with the regular keys during typing, but they do not.

What About the Dvorak Layout?

Since the keys are removable, it is possible to rearrange the keys to produce a Dvorak layout? Yes, you can. However, many of the resulting keys will be uneven and feel unnatural to the touch due to the molding from differing rows placed in new locations.

Keys create uneven bumps since molding from differing rows does not match. The tactile feel is awkward.

Practically any key can be swapped to another position. The keys are not fixed to certain places or rows except for size. For example, you can swap the Z key with the Esc key. Dvorak swapping also removes the key bumps from the home row that would otherwise be present on a Dvorak keyboard.

For Dvorak typing, I would recommend leaving the Qwerty layout as-is and memorize typing Dvorak on Qwerty due to the ubiquity of Qwerty keyboards.

Wrist Rest

Most keyboard wrist rests are hard, plastic junk, but not this one. The wrist rest supplied with the K70 has a soft, rubbery, smooth feel that makes it a joy to stroke. It’s great, and its texture matches well with the rest of the keyboard.

Anti-Ghosting

Another advertised feature is called anti-ghosting. Ghosting occurs when multiple keys are pressed together or in rapid succession and some keys are not register. By increasing the polling rate and method, this can be eliminated so PLOKTA (Pressing Lots Of Keys To Abort) or high-intensity gaming will allow all keys to register.

I have never encountered a ghosting issue, so I cannot say for certainty how well the anti-ghosting feature operates.

Quieting the Keys

The keys can be somewhat loud due to the plastic clacking noise. Not terrible, but it is not quiet. In addition, the keys have a slightly deeper press depth than what I was expecting. Is there any way to dampen the clacking sound and reduce the needed press depth?

Yes, there is, and it involves modifying the keys with rubber o-rings.

These are small, rubber rings that fit on the plastic cylinder underneath the keys. Each key needs its own o-ring. (I ignored the space bar since it was never a distraction.) I used a pack of 008 Buna-N 50A Durometer with an inner diameter of 3/16″, an outer diameter of 5/16″, and 1/16″ in width. The K70 used the entire pack of 125 o-rings.

O-rings certainly make a difference. The clack noise is barley noticeable, and the key press depth is reduced to more normal limits that I am already accustomed to. This is a worthwhile improvement that I would highly recommend.

O-Ring Installation

1. To affix a ring, remove the key and flip it over.
2. Inside the key is a plastic column. Use tweezers to affix the o-ring and press it down as far as it will go into the key.

3. Replace the key.

Some keys, such as Shift and Backspace, have three columns. If you have enough o-rings, place one on each column, but I found one to be enough.

The extra red keys do not have the four standoffs inside that the regular keys have. O-rings can be placed deeper, so use two o-rings per red key to gain the same press depth as the regular keys.

The Scroll Lock, Caps Lock, and Num Lock LEDs Do Not Work With Linux

Like any other keyboard, the K70 possesses Scroll Lock, Caps Lock, and Num Lock LEDs to indicate the status of their corresponding keys. Not just any LEDs, but pinpoint small, bright white LEDs. The LEDs work fine with Windows 7, but not with Linux. In fact, they do not work at all in Linux.

The three white keyboard LEDs are distractingly bright, so it is good that they do not work as intended with Linux. Here, we see them all illuminated. At the time of this picture, the K70 was connected to a Linux computer booted to BIOS. All LEDs function properly in Windows 7.

In Linux, the keys themselves work properly even if the LEDs do not. For example, pressing the Caps Lock key still enables capital letters. However, the Caps Lock LED will not illuminate to show that it is active.

Updating the Keyboard Firmware

Yes, you can update the K70 firmware by downloading the latest firmware from the Corsair web site and installing it using Windows 7. Maybe an updated firmware would fix the non-working LED issue with Linux?

I downloaded the 1.09R firmware (make sure you choose the correct version for your keyboard), and updated the keyboard from Windows 7 because the firmware update only works with Windows.

K70 keyboard firmware updates completed successfully in Windows 7. All three keyboard LEDs blink during the update.

Did the update fix the LEDs in Linux? No. They still do not work with Linux.

What About the BIOS Mode Switch?

No effect. In fact, this caused more problems. Setting to BIOS mode disabled the Windows disable key in Linux, and it made the Scroll Lock light blink.

What Is the Issue?

I think the issue is a software compatibility issue with X because the keyboard LEDs work fine until X is activated. During BIOS, during boot, and switching to a new TTY with Ctrl+Alt+F1 all cause the keyboard LEDs to function properly, but when X is active, the LEDs no longer function.

Any Workarounds for the LEDs?

sudo kbd_mode -u

This makes the Num Lock and Scroll Lock LEDs work, but not the Caps Lock LED, which is probably the most important of the three. This must be entered upon each reboot unless scripted.

All this command does is set the keyboard to UTF-8 mode instead of its default unknown mode. This is odd because other keyboards work fine in “unknown mode.”

sudo kbd_mode will show the current keyboard mode.

xset led and xset -led should turn all keyboard LEDs on and off, but only the Scroll Lock LED is affected.

Is This An Issue?

No. In my opinion, the non-working keyboard LEDs in Linux is an incredibly minor issue. In fact, I never use keyboard LEDs to begin with. The S3 Ultrabook has no keyboard LEDs, and yet I type without any problems.

This is most likely psychological: If something is present on the keyboard, then it should work, right?

In practice, I am glad that the LEDs do not work in Linux because they are super bright white LEDs that are too distracting to be useful. If they did work, I would be placing black electrical tape over them to block them anyway. So, for me, the non-working LEDs in Linux is a welcome feature, not a bug.

The K70 does so many other things so well, that it makes the LED issue insignificant.

Linux Calulator Pops Up When Cycling the Backlight

In Linux Mint 17, cycling the backlight from off to low opens the calculator. This is because the XF86Calculator shortcut activates when pressing the backlight brightness key. The remedy is simple. Open the Linux Mint keyboard shortcuts (System Settings > Keyboard > Keyboard Shortcuts > Launchers > Launch Calculator) and change the Launch calculator to unassigned. (Press the Backspace key to set it to unassigned.)

Summary of Linux Issues

The Vengeance K70 is plug-and-play compatible with Linux. Just be aware of a few issues:

• Booting with NumLock enabled in BIOS causes the Num Lock LED to remain lit in Linux. There is no way to turn it off.
• Setting the BIOS mode switch to BIOS will make the Caps Lock and Num Lock LEDs work, but it causes the Scroll Lock LED to blink, which is distracting.
• Switching the BIOS mode switch to other modes has no effect.
• Linux Calculator opens when cycling the backlight button.

Conclusion

The Corsair Vengeance K70 is definitely on the higher end of the keyboard spectrum. While there are minor issues with Linux and the keyboard itself is more plastic than expected, this is the best keyboard I have ever used, and I am more than happy with it! The various lighting modes, the removable keys, and most importantly, the mechanical keys themselves, make this keyboard a joy to type with.

Time will test its durability, but for now, the K70 is my new best typing friend.