Page 2 - A Closer Look - Hardware and Software
The Cooler Master SK653, like the rest of the SK-series, is a very minimalist keyboard even though it comes with a keypad. At first glance, it looks pretty much exactly the same as the SK650 I reviewed in 2019. We got a gunmetal gray SK653 compared to the White Limited Edition SK650; I will point out the hardware differences in just a moment. You can pair the SK653 with up to three devices, and it is compatible with pretty much anything Bluetooth that supports keyboard inputs including your iPhone. The SK653, just like the SK650, is one of the cleanest looking keyboards I have seen in an Apple-esque manner. You will have to look pretty closely, and in a sense, figuratively with its straight edges, no dedicated macro keys, and a reference layout to see what makes the SK653 special. Indeed, there is nothing that really sets it apart other than the fact this is a mechanical keyboard with full RGB LED backlighting. There is no integrated wrist rest and there is no specially designed OEM accessory for it. Meanwhile, the exposed gunmetal gray brushed aluminum backplate is great to look at. It even hides fingerprints well. The sides and bottom are all made out of quality plastic. Overall, I am a big fan of the looks, but the aluminum backplate flexes slightly under heavy load. It would be nice if it was stronger, but it is not a major concern.
The Cooler Master SK653 measures in at 430mm width, 125mm depth, and 25mm height. This is about as compact as a standard full-size QWERTY keyboard will go. To go along with its low profile, the keyboard weighs about 737g according to the manufacturer. This is lightweight for a wireless mechanical keyboard.
Once you turn off the lights, turn on the keyboard by a slider switch on the left and activate the Cooler Master SK653's RGB backlit keys, the keyboard really shines -- no pun intended. The font is large and easy to read. The SK653 features full independent key RGB LED backlighting, but you are better off doing that in software even though you do not have to use it. The RGB LED backlight and macros can be programmed or adjusted on-the-fly without software as outlined in the user manual. A dedicated ARM Cortex M3 is inside to run complex lighting effects like the built-in snake game.
I am a big fan of fully backlit keyboards, and I am happy Cooler Master designed the SK653 with this feature. The Cooler Master SK653's key illumination distribution is reasonably even for the most part, but there is a bit of backlight leak through the rear USB port. The area between the keys is also backlit thanks to the reflection of the LEDs, and I like it. One thing to point out, for keys with more than one line of text label, you will notice the top half is significantly brighter than the bottom half. This is due to physical design limitations of mechanical switch stems, as you can see in our photo above.
Hitting the Fn key along with the labeled F1 through F8 buttons and arrow keys allow you to do things like cycling through different lighting effects, change backlight intensity, or adjusting the effect speed. Fn in combination with F10 to Pause are for macros. The productivity keys double as your multimedia keys with Fn held down. You can even switch profiles, stored on the keyboard's 512KB internal memory, by going through Fn in concert with 1 to 4. Fn in combination with F9 toggles Win Lock on or off. For the Mac users among us, holding down Fn and Shift on the right will allow you to toggle between operating systems for specific Mac OS features like screen brightness, Mission Control, and multimedia keys along the top row. Fn + Backspace is also the eject function.
For those who are unfamiliar with different types of keycaps, the most common one found are made out of acrylonitrile butadiene styrene, or ABS, plastic. The ABS plastic keycaps on the SK653 are of average quality. They are smooth and feels nice on the fingers despite the tendency to show oily marks in the long run. A big change on the SK653 from the SK650 is standard low-profile keycaps instead of flat keycaps. Many users complained flat keycaps required some time to get used to due to spacing differences, so this is a welcomed changed in my opinion. That said, polybutylene terephthalate, or PBT, keycaps are stiffer, harder, and has better color retention.
Almost everything here is pretty standard in terms of layout with a few additions. I prefer the single row Enter key layout as present on our US QWERTY Cooler Master SK653. Keyboards with a double row Enter key usually means the "\" button is moved to the left side of the right "Shift" key; reducing the size of the latter. I am more used to having a full-width Shift on the right and a half-height Enter. Obviously, this is more or less personal preference, but having a half height Enter key makes a lot more sense to me.
The Cooler Master SK653, unlike the tenkeyless and 60% SK-series, has dedicated lock indicator LEDs. They are located above the numeric keypad labeled "N", "C", and "S" for number lock, caps lock, and scroll lock. The lock indicator LEDs are also RGB and can be configured by the user. A small LED located on the Caps Lock button is used for indicating battery status, which will change flashing pattern and/or color depending on remaining battery percentage or charge status. One omission I noticed is the backlight for the Windows key will not turn off when Windows lock is activated. Instead, the F9 key will change color when you hold down Fn. Even more confusing is when the full keyboard lock is activated. Everything looks exactly the same unless you hold down the Fn key. Those who are not familiar with their SK653 could be left wondering why their keyboard stopped working.
The dual 2000 mAh or equivalent 4000 mAh battery can last up months with the backlight off. Your mileage will vary with the RGB LEDs turned on based on your usage habits, LED brightness, and lighting effect used. The SK653 will enter into power saving mode after 15 minutes by default by turning off the backlight. The timeout can be changed in software. Charging the keyboard will take a few hours.
If you do not know what a mechanical keyboard is, there are three main types of keyboards in the market today. The cheapest is the membrane keyboard, which is the easiest to make, but also has poor typing feel and response due to squishy keys. A scissor switch keyboard has its own independent keyswitch mechanism for each key, which delivers improved tactile response and typing experience. Modern scissor switch keyboards can be very good for everyday office use. Mechanical keyboards such as the Cooler Master SK653 costs the most because each keyswitch is an independent part.
The SK653 features TTC KS32 low profile mechanical switches. Cherry MX switches are generally seen as higher end units as they are the original design from Germany, while TTC mechanical switches are imitation units from China. Our particular model has red-type switches, but the SK653 is also available with blue or brown. If you enjoy red-type switches, these low profile TTC switches feel great in operation. The TTC KS32 red's maximum key travel distance is 3.2mm with actuation at 1.3mm. The Cooler Master SK653 will feel very different than other non-mechanical keyboards with an actuation force of 45cN in a completely linear fashion. This keyswitch is desirable for gaming because you will be bottoming out all the keys anyway, but the lack of the "bump" of the TTC KS32 red may not appeal to everyone. The TTC KS32 is rated for 50 million operations like genuine Cherry MX switches. The base is strong as aforementioned, but there is some keyboard flex under heavy loads, but it is not a major concern.
For wider keys, Cooler Master opted to use Costar stabilizers. A stabilizer, as its name suggests, is to maintain the balance of wider keys. The other main stabilizer design is Cherry. The Costar stabilizer found in the SK653, as shown in the above photo, has a wire bar that spans nearly the entire width of the keycap and attached by a clip at the bottom of the keycap. Cherry stabilizers, on the other hand, uses additional non-electrically activated switches without the spring on the sides for support. Costar stabilizers are rattlier, but are easier to maintain, while Cherry stabilizers feel mushier.
The Cooler Master SK653 is a full NKRO keyboard that polls at 1000Hz in wired mode and 6KRO that polls in 125Hz in Bluetooth wireless mode. NKRO stands for N-key rollover. If you have used keyboards with limited NKRO capabilities, you may have experienced ghosting issues in the past. When too many keys are pressed at the same time, your system will be unable to register any more strokes. A full NKRO keyboard like the Cooler Master SK653 overcomes this by independently polling each key, making all inputs detectable by the hardware regardless of how many other keys are activated at the same time. This means in the event you have every other key on your keyboard depressed, it will still register the last stroke. This keyboard will only register up to six simultaneous keys in wireless mode to save battery. This is an acceptable compromise in my opinion, since you have only ten fingers.
At the back of the Cooler Master SK653 is the USB Type-C cable lead out. It comes out in the center and is used for charging the keyboard's dual internal 2000 mAh batteries or using it as a wired keyboard if you desire. This braided cable is of average thickness and extends 1.8m in length to connect to your computer via one standard, gold-plated USB Type-A connector. When we bring about the question of whether gold plated connectors are actually useful or not, let us just say if it was the actual pins, then there is a possibility since gold offers better conductivity than other metals. This theoretically establishes a better connection with your computer, but on a digital signal level, we must understand it is a discrete one or zero. If anyone tells you they can tell the difference, you can definitely defeat their theory with a double blinded test. Additionally, if you are referring to the gold part of the connector you see on the plug, I would like to point out it is only used as ground. In other words, it is nice to have, and it is pretty to look at, but it is not anything significant on a practical level. The gold-plated USB connector will not have any performance impact on the Cooler Master SK653, not to mention the SK653 is a Bluetooth keyboard and is designed to be used wirelessly.
At the bottom are four small rubber pads to help the SK653 stay in place during intense gaming sessions. The keyboard itself is pretty lightweight, so it might shift a bit if your table does not have a lot of grip. The two rubber lined flip-out risers at the front tilts the keyboard up for those who prefer it. What you will not find are keyboard drain holes, so it is advisable to keep your Mountain Dew at a distance.
The Cooler Master SK653 works along with a version of Cooler Master MasterPlus+, which is a 340MB download from the company's website at press time. This program unifies many Cooler Master peripherals into one application, but check the website first for compatibility. Once the program opens, it will immediately detect the products you own. All settings are stored on the keyboard's 512KB internal memory for up to four profiles.
The main configuration window is separated into five tabs, as shown in our screenshot above. The first tab, wireless, allows you to configure settings like timeout and LED brightness. The second tab, Lighting, allows you to select RGB lighting effects and colors. Key Mapping shows a picture of the keyboard, where you can select individual keys and change their functions. The Macros tab allows you to program macros. Profiles is where you can import and export the four profiles stored on the keyboard's internal memory. Overall, I found Cooler Master MasterPlus+ to be basic, but it is very straightforward and easy to use. It is certainly not as powerful as Corsair's iCUE or SteelSeries' GG. In fact, you can do most of the things directly on the keyboard without software, but my overall experience was positive. I do have a few complaints, which all relate to the update process. First, if a software or firmware update is available on any compatible device, you cannot launch MasterPlus+ without running the update first, which seems a bit forced. Second, the update screens all use the infamous MS Mincho Regular font and are written in poor English. I am sure Cooler Master can do better, especially for a company of this size and caliber.
Page Index
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware and Software
3. Conclusion
