Sensor and Performance

This mouse uses the PixArt 3360, the current top-of-the-line sensor. It performs just as well as you would expect. You can also see the NXP MCU on the left.


To showcase its performance, I tested the mouse in MouseTester by moving it across my mousepad's surface area as quickly as possible. The result is excellent, showing no signs of tracking loss. Judging by my test results with other PixArt 3360 mice, I'd say it's fast enough for any human to never worry about hitting malfunctioning speeds.

CPI Accuracy

The CPI steps are consistently 3-5% higher than the proclaimed value. There usually is a slight variance to CPI with all mice (i.e. you set 400 CPI, but it actually is somewhere between 390-410 CPI); however, the more accurate the better. I test these because in the past, certain mice had a very high divergence at their upper end, where 6000 CPI would really be 4900 CPI, for example. So the CPI accuracy you see below is actually good and most of all consistent. It is nothing to worry about, but it might be why the Scream One feels faster to you at the same CPI step as, say, a Zowie, given those are typically 3-5% lower than their set values in terms of CPI. It is something you get used to rather quickly when using a mouse for a longer time.

Cursor Behavior

I drew lines in Paint using the pencil tool to see if there are any problems with the cursor's path (for example: jittering, skipping, severe angle snapping, etc.). A bad result would have zig-zagging instead of smooth lines. The waves in the straight lines I drew are on purpose; they test angle snapping of which there seems to be none.


As a verdict, cursor tracking is near perfect. The path looks very clear even at the higher CPI steps, which are usually more jittery.

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 doing this test manually because I lack a test bench that is able to limit movement to the x-axis. But as I have done the same test with a variety of different mice and sensors, it's possible to compare. In this test, the angular displacements were 1.9, -1.71, -0.5, 1.71, 0.65, 4.8, -3.47, 1.03, -1.64, which is a good result. The one outlier with 4.8 is probably due to my hand movement.