Sensor

The sensor is called "TrueMove3", but is by the looks of it obviously some variation of the 3360, evident by the lens's and sensor's design. You can also see the MCU in the lower-left of the close-up, as well as the bold marketing slogan "Bow To The Master". Taking a look at the underside of the PCB, you can both see the lens and a sneaky signature from Jeff Chang, who is the product manager for mice at Steelseries.

Performance

As expected with the sensor being a 3360 variant, sensor performance is top notch. It tracks brilliantly at speeds of at least 7 m/s, probably even faster, but I could not physically move the mouse faster on my mousepad while keeping it steady.

CPI Accuracy

The CPI steps are also very close to their proclaimed values. There usually is a slight variance to CPI with all mice (i.e. you set 400 CPI, but it really is something between 390-410); however, the more accurate the better. I perform this test because in the past, certain mice exhibited a very high divergence at their higher settings, where 6000 CPI would really be 4900 CPI, for example. So the CPI accuracy you see below is actually very good and most of all consistent.


As you can see, CPI accuracy is very good; the slight spike at 3200 CPI might be a measuring error caused by me doing this manually, but it is still only about 2% above the proclaimed value even so, which is very good by itself.

Speed related accuracy variance

With this test, I show how accurately the sensor reports movement at different speeds. You can see me move the mouse at varying speeds from a starting position and back again at a different speed. In the top-right corner is the showpos command in the Source engine. The second row shows the viewing angle, of which my point of reference is mainly the second one, the x-axis angle. With a script, I set my viewing angle to 0 0 0 at the start. After every swipe back to my starting position, I record the deviation from the starting position.

There is obviously some degree of error here due to me performing this test manually because I lack a test bench that is able to limit movement to the x-axis only. I have done this same test with a variety of different mice and sensors, so it's possible to compare. In this test, the angular displacements were -0.48, 0.87, 0.20, -0.08, 1.07, 1.15, -1.11, 3.05, which is actually a very good result and as expected for a 3360 sensor.

Lift off distance

Lift-off distance for the Sensei 310 was low, barely 1 CD, so around 1.2 mm.