Gaming Mice - i.e. mice which are tailored to the needs of gamers, rather than a generic design with a few blue LEDs stuck at irregular intervals - aren't by any stretch uncommon these days. What is uncommon however is the release of wireless gaming mice, simply because it's so very hard to get right. This week peripheral specialists Logitech are throwing their hat into the ring yet again with the G900 Chaos Spectrum, a compact wireless design that aims to prove that a wireless mouse can be an exceptional choice for competitive fast-paced gaming.

Designed and Built from the Ground Up

Most gaming mice follow a formula of plastic shell and off-the-shelf internal components including switches, sensors and controllers. That's all very well if your mouse shape is part of the branding and doesn't evolve significantly over time, but can result in bloated pieces of engineering which weigh a tonne and are poorly balanced for gaming. When a large battery is also required solid design principles have to make way for a certain amount of cramming, and that can result in a sub-optimal product and end-user experience.



Logitech by contrast pride themselves on design expertise which isn't limited to collecting a range of suitable components and rigging it together to it's 'about right'. Unlike their competitors, components inside a Logitech Gaming mouse are designed in-house to allow for optimum internal layout, power consumption and weight balancing, subject to a comprehensive battery of tests. Even with this ethos in mind, the G900 Chaos Spectrum takes it to the next level.

Typical design principles for mice are that the plastic exterior is load-bearing and sized to allow for just enough space to accommodate internal components. The G900 instead incorporates a load-bearing endoskeleton - that is, an internal skeleton - with tailor-made light-weight and compact parts. An exterior can then be shaped to suit as wide a user base as possible, rather than being compromised by short-cuts necessary in the design stage. And that's going to be hugely important because the G900 is intended to be the weapon of choice for enthusiast gamers and eSports professionals alike.

The G900 weighs in at just 107g, and is one of the most light-weight mice in its class. Small touches, such as a redesigned hollowed-out light-weight scroll wheel and a thin-wall exterior moulding process, have added up to a pretty stunning result.

Sensing the Important



Whilst it's not the be-all and end-all for a gaming mouse, a high-quality sensor is hugely important for stable tracking and responsive use. Once again Logitech have a wealth of expertise to bring to bear in this arena, they were the first to introduce optical sensors to mice in the '90's, and now design and manufacture their own optical and laser sensor technology. Perhaps unsurprisingly Logitech have opted for their state-of-the-art PMW3366 optical sensor, which comes with a few perks:



The choice of an optical rather than laser sensor design is an easy one, but surprisingly the dynamics of laser sensors (including smoothing and acceleration response) weren't the only sticking point. High sensitivity and response rate laser sensors draw excessive amounts power that require either a huge battery or short session times, neither of which are acceptable for a gaming mouse. The PMW3366 is not only accurate on a wide range of surfaces, it will also down-clock from 1000Hz when idle to save power; as a result the battery on the G900 is only 800mAh, and yet Logitech still claim 32 hours continuous use.

Wireless Performance is Hard To Come By

One of the innovators in introducing wireless RF technology to mice, Logitech have an extensive back-catalogue of models with proven performance. Their new wireless gaming mouse would need to be pushed further and be even more reliable to survive the crucible that is competitive eSports, and luckily they had an ace up their sleeve: a comprehensive design and engineering facility in Lausanne, Switzerland. From here they could set up bespoke tests, subjecting both wireless communication and optical sensor to rigorous testing beyond even the competitive environments of an eSports arena, to ensure that wireless mousing was really up to the task.



First up was the relatively simple task of judging signal strength. Most wireless mice incorporate a transmitter/receiver into a base station which doubles as a charging station, but the G900 instead relies on a compact wireless USB dongle and USB charging cable. As a result signal strength needs to be both uniform to account to the different positions in which the PC (and hence receiver) could be located, and high relative to a reference level of 1mW power. When placed in an Anechoic chamber Logitech measured an 8dB averaged signal strength, multiple times stronger than their closest wireless competitors and immediately a good basis upon which to build.

Mere signal strength is not the only issue in wireless communication, interference is also a major factor in performance. Whilst a mouse may operate perfectly in optimal conditions, especially if the receiver is relatively near, bombard the environment with spurious signals and you soon see the quality of the implementation. It's a particular concern given that most wireless mice operate on the 2.4GHz band, which is already particularly congested thanks to 802.11g/n wireless networking and other proprietary signals.



Although it may appear elaborate, the testing mechanism for interference is actually straightforward. The mouse is placed on a rotating platter which sketches out a continuous circle, and the chamber is suffused with a variety of interfering signals in multiple channels. Interference in the signal will be expressed as a break in that circle, and when gaming that will be experienced as momentary pointer lag and a mismatch from where you expert the mouse pointer to be.



Logitech's testing shows their wireless implementation to be remarkably robust, with no skips or jumps. Compare that to an identical test with the next best performer, the Razer Mamba 2015.



Without interference performance is satisfactory, but introduce it and problems become immediately apparent: jitter and freezing plague the end result, in what would have been an immensely unsatisfactory user experience.

Logitech are keen to stress that this isn't an indictment of any particular mouse brand, the scenario presented is very much worst-case. It's simply a way to reassure both themselves and the gaming public at large that with the G900 a wireless connection between mouse and PC can absolutely be trusted without hesitation, even in hostile environments such as LAN parties or cramped office conditions with other wireless transmitters nearby.

Latent Concerns

Signal quality is one aspect of disquiet for wireless mice, but another is latency. Many gaming models now use 1000Hz/1ms USB report rates to reduce latency; however switch, sensor and control unit all have a part to play in ensuring it's as low as possible. By hooking up both switches and the USB output to a Tag Heuer HL440 professional timing unit Logitech measured the time differential between actuation and an activation signal being passed to the USB end-point; from this they were able to discern hardware click latency for the G900 and a selection of other mice. A similar technique could then be utilised to measure motion latency.



Using this methodology Logitech discovered that their wireless latency was actually lower than the wired latency of their competitors top gaming mice, a frankly astonishing result. Furthermore the maximum latency between click and response was 5.54ms, a suitable result even for professional gaming. The G900's motion latency profile was also similarly excellent, once again hitting the <6ms mark and proving that wireless gaming doesn't have to come with a performance down-side.



We should raise a word of caution at this point: this advanced testing was performed by Logitech behind closed doors. The methodology appears to be sound but we do not have the tools to independently confirm them. In general we'd advise you to take them with a pinch of salt, and make use of suitable return policies if your experience doesn't meet expectations.

Additional Features & True Ambidextrous Layout



Over time main mouse buttons tend to lose consistency, especially the click response which can become spongy or otherwise unsatisfying. That makes sense when you think about it - the movement of the mouse button tends to be a sheering motion on the top of the switch block, which over the course of hundreds of thousands of clicks will have an impact on how the overall system responds to force. In order to improve this, and reduce the actuation distance for the button, a redesign of the button hinge needs to be made to ensure that the actuation point meets the switch exactly parallel, a not inconsiderable feat. Enter what Logitech are calling Mechanical Pivot Key Design:



Once you have a perfectly consistent response on both left and right mouse buttons you start to have the basis of a truly ambidextrous mouse, but for gaming you also need to incorporate at least two thumb buttons. This has been the failing of ambidextrous mice for gaming - thumb buttons were either restricted to the left of the mouse (and hence were implicitly right handed) or located on both sides, leading to accidental actuation. Logitech have tried something different with the G900: replaceable magnetic buttons for both sides that can be blanked off as necessary, making it almost uniquely suited to both left- and right-handed gamers. Unused switches can then be packed away in the supplied case so they're not lost if you want to loan the mouse out.

Finally, no modern mouse would be complete without lighting. In the case of the G900 Chaos Spectrum it's restricted to two RGB lighting zones controlled through software, the DPI indicator and G logo zone. Controlled through software, each can be used to indicate the currently active profile and come with a selection of lighting effects. Logitech are also in the process of making their lighting module SDK for all their peripherals open source via Github, allowing users with programming expertise full lighting effect customisation.



Features and Technical Specifications



Logitech Gaming Software



Logitech Gaming Software, or LGS for short, has historically been Logitech's Achilles Heel. Even as they've boosted development time and resources dedicated to this important aspect of the finished product it's often not been up to the high standards set by their hardware, but they are steadily improving upon it capabilities and ironing out the flaws. The latest version of LGS, which is downloaded from the Logitech support site rather than included in the mouse package, controls customisation for the mouse and also provides an optional software macro layer for game-specific profiles.

In addition to a battery indicator (which predicts the number of hours use remaining), DPI level configuration, on-board profile and macro editor, and lighting customision, the LGS also supports game auto-detect and profile loading. Logitech have created a series of button profiles for some of the most popular games which (optionally) are activated when the game launches and reverts upon exit. These profiles can of course be edited too, allowing newcomers to tweak it as they see fit without impeding a power user.

Final Thoughts

The G900 Chaos Spectrum is at first glance a hugely impressive piece of gaming technology that Logitech have poured an enormous amount of resources into. Our hands-on review will speak for itself, but the underlying message that Logitech want you to come away with is that wireless gaming mice need not be a compromise and are absolutely viable for even professional level gaming. The one downside to all this complex design, cutting-edge technology and rigorous testing is that it will be reflected in the price.

The mouse will be available from the beginning of April with a suggested retail price of $149.99 in the US and €179 (inc. V.A.T.) in the EU, which is effectively an industry benchmark for high-end wireless gaming mice. For comparison the $149.99 MSRP is identical to Razer's Mamba and Ouroboros, and €179.99 is what you'd expect to pay for the Sensei Wireless direct from SteelSeries.

More information on the G900 Chaos Spectrum can be found at the Logitech Blog as well as the product page.