u/KennKennyKenKen

About 10 years ago, I figured out some methods to detect and measure smoothing in MouseTester. If you've ever heard of something like 3360 has X frames of smoothing above Y dpi, these OCN posts are where it was first discovered.

Sadly, the mice forum on OCN is now basically dead. But even more sadly, smoothing is still alive and well on modern sensors.

Here's my full blog post, focusing on the PAW3950: https://xbabtech.com/blog/smoothing/

PAW3950 summary table:

Setting	DPI ≤ 5000	5050 ≤ DPI ≤ 10000	DPI ≥ 10050	Set-down interval (all DPIs)
Ripple Control disabled (3950 stock)	None	2 frames	2 frames	16 frames
Ripple Control enabled	None	2 frames	16 frames	16 frames
Smoothing disabled	None	None	None	2 frames

I know this contradicts common community knowledge and probably also some claims made by usually trustworthy people. But everything here is backed up by real data, not my "feels". Most of the evidence is in the blog post, and if you want any more info or data, reply here or find me on Discord.

Here are some key findings:

1. PAW3950, using stock settings, configured in any sensor mode (corded gaming, high performance, etc) has 2 frames of smoothing above 5000 DPI. This is the "Ripple control disabled" row in the table. Ripple control increases this at very high DPI, unsurprisingly. The surprise is that smoothing isn't fully disabled even when ripple control is off.
2. PAW3950 in corded gaming modes (afaik, what all 8k 3950 mice use) has an enormous 0.45 second period after set-down, as in lifting and placing mouse down on pad, where smoothing is increased to 16 frames. This affects all DPIs, even below 5000. The first image above shows an example.
3. It's not just PAW3950. The Viper V4 Pro's latest and greatest 50k DPI sensor has an even more ridiculous 1.5 seconds after set-down where the data has decreased noise. I suspect this is smoothing as well, but I haven't fully investigated. Even more strange, it seems the DPI different from nominal in this 1.5 second period (see the sudden jumps in the velocity traces of the second image).
4. For the PAW3950, I figured out an undocumented register setting to disable smoothing in normal tracking at all DPIs. The set-down smoothing is not disabled, but greatly decreased down to 2 frames (last row in table). I also figured out settings to decrease the set-down interval to 12 ms. With these settings, the PAW3950 is almost entirely smoothing-free at all DPIs. This is what my mouse (XA25) will be using by default.

My main takeaway is that all sensors are guilty (of smoothing or other odd data processing) unless proven innocent. I still need to investigate the 3399, 3395, and 3955, but given what I see already in the Viper V4 Pro, I wouldn't be surprised if all of these sensors have similar behaviors.

1. Oscar Isaac and Carey Mulligan

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2. Ryan Gosling and Emma Stone

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3. Adam Sandler and Drew Barrymore

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4. Tom Hanks and Meg Ryan

Just get a steam deck