Interior: Testing 3G Laser

It is not the revised shape or the amount of buttons that is the key feature of the Lachesis. It is the third-generation laser sensor with a huge resolution and a few improvements concerning other key parameters.

An increased optical resolution was the main advantage of early laser-sensor mice over ordinary optical mice. The first generation of laser mice reached 2000dpi. For optical sensors it is the maximum real (not interpolated) resolution. For example, the Razer 3G optical system has a resolution of 1800dpi, being a mere 200dpi better than the second generation. The higher values declared by some manufacturers like A4Tech are arrived at by means of software interpolation. As a matter of fact, such mice have a lower positioning accuracy than the true 1800dpi.

Anyway, the physical resolution is not the only key parameter of a laser sensor just as the frequency in gigahertz is not directly linked to CPU performance. There are two parameters in which first- and even second-generation laser sensors were inferior to optical mice. It is the maximum tracking speed and the height at which the sensor “loses” the surface when lifted up above the pad.

Perhaps you don’t know what the generations of laser sensors mean? The first generation covers most of the models available on the market, beginning with the firstling Logitech MX1000. The Razer Copperhead and the Microsoft Sidewinder belong to it. Their sensors have a resolution of 2000dpi, a maximum tracking speed of about 45 inches per second, and a max acceleration of 20G. The second generation includes the Logitech G9, SteelSeries Ikari Laser, and Saitek Cyborg. These mice have a resolution of 3200dpi and a tracking speed of 45-65ips. Finally, the third generation debuted with the described product – Razer decided to skip 2G lasers altogether. Take note that such models as DeathAdder, Diamondback 3G and Boomslang 2007 CE use a 3G sensor too, but it is an optical sensor with infrared highlighting. You can refer to our review of the Razer DeathAdder for more details about the genealogy of the optical systems.

So, we’ve got a third generation of laser sensors now. According to Razer, the key parameters of 3G sensors are:

• resolution of 4000dpi
• hardware adjustment of the resolution stepping 125dpi
• tracking speed of 100 inches per second
• maximum acceleration of 25G
• minimum height sensitivity

It’s all clear about the first point. The Lachesis will please every person who prefers high sensitivity. When you select the highest resolution and disable all software filters, the mouse becomes very brisk, outperforming any opponent. It means that complex movements (such as moving through a few screens in a real-time strategy) can now be performed with fewer movements of the mouse.

The option of fine adjustment of the sensor resolution is valuable because you can fine-tune the physical resolution to your taste and do this without software tools. In other words, the settings can be saved in the mouse itself and used later even if the driver is not installed. Laser sensors used to change the resolution in a few steps (e.g. 400, 800, 1600 and 2000dpi). The Lachesis has five levels of resolution but each of them can be set at any value in a wide range with a step of 125dpi. For example, the bottom level is set at 500dpi by default but you can set it at anything from 125 to 875dpi stepping 125dpi. The top level can be selected from 2125 to 4000dpi. The settings are saved in the mouse’s memory and are always available for use. I should note there have appeared a few more products allowing such a flexible adjustment of the sensor’s resolution (e.g. Zalman FPSGun FG1000 and SteelSeries Ikari Laser) since the release of the Lachesis, but Razer was the first developer to introduce this feature. By the way, the concept of switching the mouse’s sensitivity quickly, which is now offered by every manufacturer, was invented by Razer, too. In 1999 the On-the-Fly Sensitivity option was available in the Boomslang 2000.

The tracking speed has been the weakest spot of the laser technology. Ensuring a highest resolution even in the first generation of products, the developers of laser sensors neglected this very important parameter. As a result, the mouse could hardly be used at low sensitivity. When the gamer made a sudden long movement, typical for such mouse settings (the aiming accuracy improves when the pointer speed is lowered), the pointer would lose the desired trajectory because the sensor could not process the high-speed movement of the mouse. That’s why a year ago Razer was promoting the non-laser DeathAdder as a solution for people who preferred low sensitivity. The new 3G sensor provides a maximum tracking speed of 100 inches per second, which is two times the performance of the Copperhead as well as other first-generation products. It is easy to prove this fact even if you, like me, prefer high mouse sensitivity in games. With the mouse acceleration disabled, you select the minimum sensitivity (i.e. 1) in the Razer driver and set the dpi value at 500. This makes the mouse very slow as the pointer moves by only 50 pixels per each inch of the mouse movement. Thus, when you shift the mouse quickly right and left on a large pad you can move the pointer by 300-500 pixels. To make the test even more complex I reduced the pointer sensitivity in Windows XP, lowering its speed more. The Lachesis never lost the pointer even when working at such barbarous settings. The OCZ Equalizer, a first-generation laser mouse I took for comparison, could not pass this test, moving the pointer chaotically. The Razer Copperhead coped but poorly with the job, too. On the other hand, the SteelSeries Ikari Laser (2nd generation, 3200dpi) passed the test successfully. The declared tracking speed of 100 inches per second is excessive for any conditions as no gamer can move the mouse by 25 centimeters (10 inches) in 0.1 second. Thus, the problem of the lost pointer is finally solved for laser mice.

What about the maximum acceleration? This parameter is 15G for the best optical mice, 20G for first- and second-generation laser mice, and 25G for the Lachesis. To remind you, 1G equals 9.8 meters per second. You cannot move the mouse with an acceleration of 200 meters per second, so this parameter is only interesting for the marketing people, especially as it has no direct relation to the tracking speed.

I guess you may want to know how to achieve the ideal precision of pointer movements. The sensor gets hardware data about the movement, but these data can be processed by the software filters of the driver or the OS. In order to avoid any software adjustments, you should do the following:

• Disable mouse acceleration in Windows (Control Panel → Mouse → Pointer Options → Enhanced Pointer Precision → Off)
• Set the pointer speed slider into the middle position (it is easier to this in the Razer driver by selecting Advanced Sensitivity → Win Pointer Speed → 5)
• Disable acceleration in the Razer driver (if it is turned on) because it is another acceleration mechanism
• Choose the maximum sensitivity (10) in the Razer driver. The reduction of this parameter is implemented through a software filter which lowers the pointer speed by 10% relative to the hardware value

After that, the only parameter you have to set up is the hardware resolution of the sensor. Without any software processing, the dpi value is exactly the number of pixels the pointer will move on your moving the mouse by one inch. Thus, 2000dpi means that the pointer will travel 2000 pixels exactly. Thanks to the fine adjustment of the sensor resolution with a step of 125dpi you can have the desired mouse movement speed without software solutions.