Cooler Master CK721 Review (Page 2 of 3)

Page 2 - A Closer Look - Hardware and Software

While other Cooler Master keyboards we have seen recently have been low-profile affairs, the CK721 has both old and new styling merged together. Its standard height keycaps are all packaged into a smaller body with a nice gunmetal aluminum plate at the top. Its brushed surface and chrome-like chamfered edges add an accent of sophistication. These cornered off sides can be found around the keyboard and on the volume knob at the top right corner. The metal plate does add a bit of fanciness, but the older non-island design is a bit of an interesting choice. However, this design is also because the metal frame is removable so that users can potentially swap out the plate with another color or print their own cover. I do appreciate the fact that Cooler Master openly advertises this swappable frame, as well as other accessories to be purchased after the fact to make the keyboard yours, but these are all available at an additional cost. If you are interested, Cooler Master also has a white and silver version of the CK721 with white keycaps.

The dimensions are a bit larger than what a typical 65% keyboard would be with the thick metal rim around the Cooler Master CK721. This keyboard takes up a bit more space than what you might expect for a keyboard with this number of keys at a width of 334mm and depth of 118mm. The height varies based on which feet are extended underneath, with a minimum height of 37mm and a maximum height of 46mm. In terms of heft, the Cooler Master CK721 tips the scales at 764g for the keyboard alone, which is again a bit more than you might expect at this size. However, this makes sense when you consider the large metal frame and plastic shell that make up the body. Unfortunately, these materials can easily flex, especially when pressed in the middle of the keyboard. This is because the frame and shell are two separate pieces that are not well attached to each other. Instead, the top frame shifts about at the top, moving slightly left and right when pushed. These two factors make the CK721 feel a bit less premium despite its good appearances and material choices. Otherwise, Cooler Master has thrown in a foam wrist rest, which helps to elevate the users’ palms and reduce the wrist extension. It does not attach anywhere to the keyboard itself, but I do appreciate the inclusion of it.

As I have mentioned, this is a 65% keyboard with a QWERTY ANSI layout. The whole keyboard is generally standard, although there are some layout changes due to its chopped down size. For example, the bottom row uses 1U sizing for the right Alt, Fn, and Ctrl keys. This allows for the cluster of arrow keys on the right. Similarly, the right Shift key is not as wide to accommodate the Up key. At the top, we have no F keys here, while the right side is missing the number pad and the cluster of six keys above the arrow keys. Instead, the right side has non-standard positions of Delete, Page Up, and Page Down. The rest of the keys in the cluster have been moved into secondary functions. There is a single indicator light for Caps Lock near the arrow keys. There are actually two lights in that area, but the top one is used for Caps Lock, while the bottom is used for wireless status.

Moving to the secondary functions, we have quite a few on the Cooler Master CK721. All of them can be actuated with the Fn key followed by the corresponding key. There are many secondary functions, so I will go over a handful of them. Starting from the top, all of the keys on the top number row up to the "=/+" key can be used for F1 to F12. I, O, and P are used to replace Print Screen, Scroll Lock, and Pause. The square bracket and quotations key are used for Insert, Home, and End. Four onboard profiles can be chosen using the letters Z to V. "M" is used to lock the Windows key or the whole keyboard, although there is no dedicated lock indicator for this. Macro recording and playback can be executed with the keys S to J. Your typical media and volume controls can be found on the right side of the third and fourth rows. Down the right side, Delete, Page Up, and Page Down allow users to choose between the three saved Bluetooth connections. You probably have already noticed the duplicate legends, especially with the media keys, and this is to support both Windows and macOS. To switch your keyboard between the two OS, you can use the right Shift key. Finally, there is a multipurpose knob at the top corner, allowing users to cycle between different functions. By default, this works as the volume knob and can be pressed to mute. However, in different profiles, it will act in different ways too. All of the shortcuts can be found in the quick start guide, including specific ones for both operating systems.

The keycaps on the Cooler Master CK721 are made out of ABS, or acrylonitrile butadiene styrene, plastic. I prefer PBT keycaps over ABS, as they are harder, keep their color better, and do not shine or look greasy after prolonged use. ABS keycaps are the more economical option. These use a typical OEM profile. The keycaps are laser engraved, which means the keycap is painted over in the opaque color, and the legends are etched out with laser. The choice of font is clean and very legible. The keycaps use standard MX stems, which is no surprise considering we have TTC switches underneath.

As for key rollover, the Cooler Master CK721 offers NKRO over USB and 6KRO over Bluetooth. NKRO is abbreviated for N-key rollover, which refers to the number of keys independently scanned by the hardware. This fixes issues of ghosting found on cheaper keyboards. While ghosting is a marketing term, there are cases where keyboards will not be able to recognize more than one keystroke at a time, causing for missed keys. This can be frustrating when you are playing games or even if you are just a very fast typist. On an aside, the original usage of ghosting in keyboards actually referred to a third key being registered when two other keys were pressed, which thankfully is not a problem with most modern keyboards. The compromise to reduce to six-key rollover on wireless is an understandable one, as it should help with battery life, and most people will not be pressing six keys all at once.

Before continuing on, one of the selling points of the Cooler Master CK721 is the key switches. There are three main types of keyboards in the market today. The cheapest but most common is the membrane keyboard, which is the easiest to make, but also has poor typing feel and response due to squishy keys. Next is a scissor switch keyboard. This can be thought of as an enhanced rubber dome with two extra interlocking plastic pieces connected to the key and the keyboard. This creates a better tactile response and typing experience in comparison to the aforementioned membrane. Mechanical keyboards cost the most, because each key switch is an independent part. These switches are generally composed of a base, stem, and spring, with varying degrees of tactile and audible feedback.

Our unit of the Cooler Master CK721 features TTC Red switches. This features a linear travel and relatively light pressure required to push the switch. According to TTC and Cooler Master, these key switches are guaranteed to last fifty million actuations. You can see a lot of the specifications are similar to the Cherry MX Red switches, as these are clones. This means we have an initial actuation distance of 2mm and an overall travel distance of 4mm. It has an actuation force of 45g. We have top mounted LEDs, which will shine directly under the top-facing legends. Otherwise, the longer keys are balanced with Cherry-style stabilizers.

Flipping to the back side, a small area has some certification information and a serial number sticker to identify the Cooler Master CK721. In the bottom two corners, there are sizeable rubber pads to keep the keyboard in place. As for the feet, we actually have two feet on each side, propping up the keyboard to various heights. This is pretty neat to me, since I have not seen a multiple height keyboard in quite a while. All of the feet are tipped with rubber to ensure they stay in place, and the feet also have more rubber facing down in case the user does not want to actually prop the keyboard up at all. Otherwise, not pictured here is the USB Type-C connection, which sits on the back edge in the middle of the keyboard.

As for the accessories, we have quite a few included with the Cooler Master CK721. First, we have the large wrist rest, which spans the same length as the width of the keyboard. It has a purple outline of the Cooler Master logo in a corner. Otherwise, the wrist rest is not braided by any means on the side, which means the top cloth could technically come apart from the bottom rubber base. I personally would have also liked to see some sort of mechanism to keep the wrist rest and keyboard attached to each other. The next accessory is the wire keycap puller, which is nice to see. It is also more flexible than the plastic keycap pullers that are usually provided. Beside this is a wireless extender, which works in conjunction with the 1.8m braided USB Type-C to Type-A cable provided to bring the wireless transmitter closer to the keyboard.

As this is a wireless keyboard, there is also a small USB transmitter and receiver that slots into the left side of the keyboard when it is not in use. The right side has a mode selector switch, with three options of Bluetooth 5.1, wireless with the dongle, or USB. Inside, we have a 2000mAh battery that is said to keep this keyboard powered for 73 hours with the lights turned off. Personally, I think the estimate was reasonable, but this battery life is still too short for my liking. In fact, while testing over the wireless dongle, my keyboard went through mixed usage of just under six days before it needed a recharge, leaving it to sleep when I was not using it. When the keyboard is plugged in for charging, an indicator light under the Caps Lock glows red until it finishes charging. Furthermore, when the keyboard is trying to connect, whether over Bluetooth or with the dongle, the light breathes blue until it connects.

I have been using the Cooler Master CK721 for over a month now and I have generally been happy with the keyboard. I did have to make some adjustments, especially as I did not have any function and right-side keys to access directly. Typical shortcuts like Alt+F4 required another finger to press the Function key, which is a bit unfortunate. In addition, I had to forget my muscle memory in finding keys like the Delete keys. The shorter keys on the right, including Shift, Alt, and Ctrl did trip me up a few times when I was pressing key combinations, but it was also something I had to get used to. I will say that I was super glad to see the corner knob for quick adjustments, even if they were just for volume. While this volume knob is not standard on every keyboard, I think any keyboard that has one should get props for their inclusion.

As for the typing experience, I am quite used to linear switches, but the TTC Red switches felt slightly different from its counterparts from Cherry and Gateron. With the TTC Reds, we have a light feel and generally smooth travel. In addition, the feel was consistent across the keys, which is good to see. Longer keys like the Enter and Space bar also felt similar, regardless of pressing on the side or in the middle of the key. However, bottoming out the keys also felt a tad squishier than I would have liked. There was a bit of key wobble as well, but this is not too far off from most switches. There were no issues of debouncing or chattering while testing the Cooler Master CK721. As such, the whole actuation feel is really a preference thing. In reality, the biggest annoyance I had with the typing experience of the Cooler Master CK721 was the sharp metallic ping heard on every keypress. This is due to the top metal plate resonating, as it is not as firmly mounted in place. As such, the metal noise was very prominent and took away from the typing experience altogether. Even with the keyboard placed on top of a cloth mousepad, the metal sounds were irritating to hear.

The legends on the Cooler Master CK721 with its north-facing LEDs resulted in generally bright keys illuminated for their primary functions. However, secondary functions were much less illuminated, and almost faded. In broad daylight, this is not as big of a deal, but in darker environments, the uneven lighting may affect legibility of the front legends. As for changing effects, Cooler Master has let users cycle through different static and reactive effects. This is all contained as secondary functions on the keys Q to U, as well as on the arrow keys. Q lets you cycle the static color. W, E, and R are used to custom pick the red, green, and blue levels, respectively, for the backlight. T is used to cycle between the different effects, while Y and U let users change lighting foreground and background effects. Finally, users can cycle between four different levels of brightness with the A key, as well as turn them off altogether. The Up and Down arrow keys are used to speed up or slow down certain effects, while the Left and Right arrows switch the lighting effect direction. Overall, the lighting customization is impressive, especially as you can choose specific colors on-the-fly.

As with other recent Cooler Master peripherals, the CK721 uses the company's MasterPlus+ software. The download size for this utility is 310MB. In general, using the software was a consistently positive experience with a few hiccups. I did receive some firmware updates for the keyboard as well, but I found the process to be a bit strange. For one, it forces users to plug in the wireless dongle and connect wirelessly. You would think connecting with a direct wired connection is the best way to perform an update. Secondly, the fact you need to have both connected in order for any firmware to be updated is a bit strange to me. Thirdly, you cannot launch the program without updating the firmware first, which seems a bit forced. Lastly, you cannot configure the CK721 over Bluetooth. That said, once everything was up to date, MasterPlus+ functioned and was able to work with the keyboard.

As for the MasterPlus+ software, the program generally works well. Specific to the CK721, there are a total of five different configuration pages. The first tab is marked Wireless, where users can change the sleep timer and low power mode to reduce power usage when the battery is low. The second tab is called lighting, where users can pick different lighting modes as well as set their own custom modes if they desire. Under the third page, Key Mapping, users can choose what each key will execute, including different keyboard commands and macros. Under Macros, users can create and record macros to be assigned to different keyboard commands. Finally, you can save up to four different profiles and settings in the Profiles tab. Unfortunately, you can see the scaling is still an issue with MasterPlus+, as the words are still too small for the size of its window. This is a minor gripe, but it should be fixed.

Page Index
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware and Software
3. Conclusion