The Sensor

Introduction

• Sensor = the 'eye' of the mouse. It sits on the bottom and tracks movement.
• Your mouse has a tiny camera. It takes THOUSANDS of photos of your pad every second, compares each photo with the last one, and works out which way you moved.
• Bad sensor = crosshair jumps. Like aiming with blurry glasses.

How it works (side cut view):

1. Optical vs Laser

• Laser: older sensors (around 2012, e.g. Avago ADNS-9800). Tracked on more surfaces but read too deep into the pad texture -> unwanted acceleration.~ like: a camera that sees every fibre of the cloth and gets confused.
• Optical: what almost every serious gaming mouse uses today.

2. Who makes the sensors?

• PixArt (Taiwan): the KING. Nearly every gaming mouse uses a PixArt sensor. Became a patent powerhouse after buying Avago's optical sensor division.e.g. Zowie, Vaxee, Pulsar, Lamzu + dozens more built their wireless mice around the PAW3395.
• Logitech: makes its OWN sensor called HERO. Only in Logitech mice.
• Razer: 'Focus' sensors, co-developed WITH PixArt, sold under Razer's name.
• Ninjutso: 'AimNinja' sensors, developed with PixArt (more in section 7).
• Glorious: 'BAMF' sensor in the Model O Wireless, also made with PixArt.

-> Razer Focus, AimNinja, BAMF = brand names on PixArt-made tech.

• SteelSeries: 'TrueMove' sensors - SteelSeries' own name for its sensors.
• Corsair: 'Marksman' sensor - spec lists show it as PixArt-based.
• Budget brands: cheap mice sometimes use lesser-known sensors -> check before you buy!

~ like: PixArt = big engine factory. Razer pays for a special engine first. Others buy the regular engine. Logitech builds its own.

3. Specs: real vs marketing

• DPI / CPI: how far the cursor moves per inch. Boxes say 30K-50K, pros mostly play 400-1600. MARKETING
• IPS: max tracking speed. 650 IPS = ~16.5 m per second - no human arm moves that fast. MARKETING
• LOD: lift-off distance: how high you lift before tracking stops. REAL
• Motion sync: syncs sensor data with the PC -> smoother, tiny latency cost. REAL
• Glass tracking: does it track on glasspads? REAL (important if you use a glasspad).
• CPI deviation: set 800 DPI, real result 760? Most listings don't mention this - you can test it yourself.

Hidden settings (should usually be OFF for gaming):

• Smoothing: sensor averages movements -> feels floaty + slightly delayed. Flagship sensors have none.
• Acceleration: cursor goes further when you move faster -> same hand move, different result. Bad for aim.
• Angle snapping: straightens your lines. Nice for drawing, bad for aim -> keep OFF.
• Ripple control: hides jitter at very high DPI but adds smoothing -> usually OFF.

~ like: autocorrect on your phone - helpful for typing, annoying when you want EXACTLY what you typed.

Firmware matters!

Same sensor in 2 mice can feel DIFFERENT, because each mouse has its own MCU + firmware.

e.g. two PAW3950 mice from two brands will not feel 100% identical.

So don't assume: a listing that says "has a 3950" isn't automatically perfect. Test it in your first week.

DPI inflation: the 'fake' big numbers

• Every sensor has a RATED (native) resolution. Going above it means the MCU/firmware 'guesses' extra counts = interpolation.

~ like: zooming a small photo on your phone - it gets BIGGER, not SHARPER.

e.g. PAW3950 is rated 30,000 DPI, yet some listings advertise it as 42,000 DPI -> the extra is beyond the sensor's rating.

• Native steps: DPI values the sensor was designed to output cleanly (often round steps like 400 / 800 / 1600 / 3200). Odd values like 1030 may be scaled.
• Why it can hurt: guessed counts can add tiny jitter or inconsistency - some firmware adds smoothing to hide it.
• Honest update: sources DISAGREE on flagships: some testers say modern sensors (3395 / 3950 / Razer) track cleanly even at their high RATED numbers. The clearer red flag = numbers ABOVE the sensor's rating, or a budget sensor with huge DPI.

-> Before you buy: check the RATED DPI, check the sensor name, and remember pros mostly use 400-1600.

Sensor angle (rotation) - why your 'straight' swipe goes crooked

• Sensor angle / rotation: a setting that rotates the sensor's output a few degrees so YOUR natural side-to-side swipe becomes perfectly horizontal on screen.e.g. Razer has a free online rotation tool: swipe side to side 10 times, it recommends an angle to enter in Razer Synapse.
• Not the same as angle snapping: angle snapping FORCES lines straight (bad for aim). Angle rotation just CORRECTS your grip tilt.
• Sensor position matters: a small tilt on a front-mounted sensor causes a bigger cursor drift than on a centre sensor.

~ like: a crooked camera on a tripod - you don't change the view, you just straighten the camera.

Motion Sync vs Frame Sync

• Motion Sync: lines up the MCU's reports with the moments your PC asks for data -> smoother, more consistent tracking (tiny latency cost). Common on PAW3370 / 3395 class sensors.
• Frame Sync: goes one step further: also lines up the SENSOR's photos with the MCU + polling cycle. Before, sensors still took extra photos between polls.e.g. Razer Focus Pro 50K Gen-3 (Viper V4 Pro) - Razer calls Frame Sync the industry's first, with faster, more consistent aim + better battery (no wasted sensor photos).e.g. Ninjutso AimNinja 2 Pro also advertises 'FrameSync' - described as next-gen MotionSync.

~ like: Motion Sync = the waiter brings your plate exactly when you sit. Frame Sync = the chef also cooks it at exactly the right moment - no food wasted.

~ like: same idea as G-Sync / FreeSync on monitors: sync the hardware to the data.

4. PixArt: naming + ladder

How to read a PixArt name, e.g. PAW3955:

P PixArt

MW / AW MW = mostly wired, AW = made for wireless

3955 just a model code

!! Bigger number does NOT always mean better. PAW3311 is budget even though it came after the PMW3360.

PMW vs PAW - do wired mice use PMW sensors?

PMW (older) made mostly for wired

PAW (newer) made for wireless, now used in BOTH

• PMW3360
• PMW3366 (Logitech only)
• PMW3389
• PAW3311 (budget)
• PAW3370
• PAW3395
• PAW3950 / 3955

• Old days: PMW for wired, PAW for wireless (PAW = low power).
• Today: the newest + best sensors are all PAW, so WIRED mice use PAW too. Low power doesn't hurt a wired mouse!

Rough tier match (PMW vs PAW):

PMW3389 ↔ PAW3370 similar class (~400 IPS era)

PMW3360 ↔ PAW3311 older / budget class (rough)

no PMW match ↔ PAW3395 / 3950 / 3955 PAW only

Endgame Gear wired history (PMW -> PAW):

XM1 (original) → PMW3389 widely listed

XM1r → PAW3370 refresh = switched to PAW

OP1 / OP1 8k → PAW3395

OP1 8k v2 / XM2 8k v2 → PAW3950 'egg'

-> Endgame Gear is one of the best-known WIRED brands - and even they moved to PAW sensors.

(they also make wireless now: XM2we, OP1we, XM2w 4k v2, OP1w 4k v2)

PixArt ladder:

1. PAW3955 - 2026, newest flagship
2. PAW3950 - 2024, flagship
3. PAW3395 - 2022, still excellent
4. PAW3370 - older flagship
5. PMW3360 / 3389 - old classics
6. PAW3311 - budget

Mice using them:

• 3955: G-Wolves (Fenrir Pro, Lycan 8K, Warg 8K, VUK Medium, HTS Plus Pro, HTX Mini Asym) + VGN, Akko, ATK, Xiaomi
• 3950: Lamzu, Endgame Gear, WLMouse, ASUS
• 3395: Zowie, Vaxee, Pulsar, Lamzu, Ninjutso
• 3311: many budget mice

What improved each time:

3370 → 3395 + hardware motion sync

3395 → 3950 LOD 1.0 -> 0.7mm, ~8% more efficient, reliable on glass

3950 → 3955 40K DPI, 60G, adjustable virtual sensor centre

-> for ~80% of buyers, the 3395 is the best-value choice.

Story: G-Wolves x PAW3955

G-Wolves went ALL-IN on the PAW3955: Fenrir Pro (~18.9g!), Lycan 8K (~28.8g full-size), Warg 8K (~28.9g), VUK Medium, HTS Plus Pro (magnetic switches), HTX Mini Asym.

Almost all pair the 3955 with a Nordic 54L chip + 8000Hz polling.

One brand shows where the whole industry is heading - lighter + newest sensor + newest chip.

PAW3950 has many versions (confusing for buyers!):

• PAW3950: the normal one: 30K DPI, 750 IPS, 50G.
• PAW3950 MAX: spec lists show 42K DPI, 750 IPS, 70G.
• PAW3950 Ultra: spec lists show 45K DPI, 900 IPS, 85G.
• PAW3950 HS: used in WLMouse Strider.
• PAW3950 🥚: Endgame Gear's custom version (the 'egg' sensor).

~ like: same phone model with different storage + camera versions - check WHICH version you're buying.

Endgame Gear wired mice:

XM1r → PAW3370 Kailh GM 8.0 switches

OP1 → PAW3395 STM ARM Cortex-M4 MCU, 1000Hz

OP1 8k / XM2 8k → PAW3395 Nuvoton MCU, 8000Hz

OP1 8k v2 / XM2 8k v2 → PAW3950 🥚 Nuvoton, 8000Hz

Story: The Egg Sensor

'🥚' is the computer code for the egg emoji. Endgame Gear's short name = EGG. So their custom sensor is basically named 'egg'.

Also: wired mice are always connected to the PC, so they don't need power saving -> full speed all the time.

5. Logitech: naming + ladder

• HERO: High Efficiency Rated Optical -> the goal is saving battery.
• 16K / 25K: = max DPI. HERO 25K = 25,600 DPI. (Different from PixArt's code!)
• HERO 2: a brand-new generation, not just a DPI bump.

Logitech ladder + mice:

1. HERO 2 - G Pro X Superlight 2
2. HERO 25K - Superlight, G502 X, G502 HERO, G703, G903, G309
3. HERO 12K - G305 (budget wireless king)
4. PMW3366 - original G Pro, G502 Proteus, early G403/G703/G903
5. 8K budget sensor - G203 / G102 (not HERO)

What improved each time:

HERO (2016) → HERO 16K (2018) new lens, no accel/smoothing

HERO 16K → HERO 25K (2020) more DPI via FREE software update

HERO 25K → HERO 2 888 IPS, 44K, dual array for lifts/tilts

Late 2024: Logitech's '8/88/888 update' gave HERO 2 -> 8kHz polling, 88G, 888 IPS.

Story: The free upgrade

Logitech kept old shapes and swapped in new sensors: G502 -> G502 HERO, G403 -> G403 HERO...

Then G Hub updated many mice from 16K to 25K for FREE. Old owners got a new sensor without buying a new mouse!

Before you buy: 'G502' and 'G502 HERO' look the same but have different sensors - check the box.

6. Razer: naming + exclusive deals

How to read a Razer name, e.g. Focus Pro 50K Gen-3:

Focus sensor family

X / + / Pro tier: X = budget, + = older flagship, Pro = flagship

50K max DPI (like Logitech)

Gen-3 generation

Before 'Focus', Razer used names like the 5G sensor (= PMW3389, used in DeathAdder Elite).

Razer name -> PixArt twin:

5G → PMW3389 widely reported

Focus+ 20K → PAW3399 exclusive version

Focus Pro 30K → PAW3950 confirmed (Basilisk V3 Pro)

Focus Pro 35K → no public twin Viper V3 Pro, DeathAdder V3 Pro

Focus Pro 45K → not confirmed newer Razer mice

Focus Pro 50K → newest Gen-3, Frame Sync (Viper V4 Pro)

The exclusive deal pattern:

Focus+ (2019) → PAW3395 (2022) Razer first, then everyone

Focus Pro 30K (2022) → PAW3950 (2024) Razer first, then everyone

Focus Pro 35K/45K/50K → not public yet watch this space

Is there a time limit?

Contract terms are PRIVATE - nobody outside knows the exact length.

But the pattern shows about 2-3 years of Razer-only use, then PixArt sells it to all brands. Logitech did the same with the PMW3366 (Logitech-only PixArt sensor).

~ like: a new phone colour only one store sells at launch - later every shop gets it.

Before you buy: read this as 'widely reported, pattern shows 2-3 years' - NOT 'the contract is exactly 2 years'.

7. Ninjutso: AimNinja

AimNinja works like Razer Focus: Ninjutso's own name on a sensor developed WITH PixArt.

How to read the name, e.g. AimNinja 2 Pro 45K:

AimNinja sensor family (Ninjutso)

2 generation

Pro tier

45K max DPI

AimNinja ladder + mice:

1. AimNinja 2 Pro 45K - Sora V3 (40g)
2. AimNinja (upgraded) - Sora V2 8K
3. AimNinja (gen 1, based on PAW3950) - Ten, Ten Air

• AimNinja (gen 1): based on the PAW3950, 30,000 DPI. Ten Air pairs it with 8000Hz polling.
• AimNinja 2 Pro 45K: Ninjutso calls it an exclusive dual-optical engine with gen-2 motion sync, and claims up to 52% more power efficient than PAW3950.

(52% = brand claim -> test battery life yourself before repeating it)

8. Which sensor = which? (rough tiers)

HERO 2 ↔ PAW3950 / 3955 today's top class

HERO 25K ↔ PAW3370 25K was a software bump

HERO 16K ↔ PMW3389 both ~16K DPI, ~400 IPS

PMW3366 ↔ PMW3360 same classic era

AimNinja gen 1 ↔ PAW3950 Ninjutso Ten / Ten Air

AimNinja 2 Pro ↔ PAW3950 Ultra specs match, not confirmed

AimNinja 2 Pro also shares 'FrameSync' with Razer's newest Focus Pro 50K -> same newest generation.

PAW3395 sits between HERO 25K and HERO 2. Razer Focus Pro 30K = PAW3950 (top row).

9. Logitech vs PixArt (companies)

• Who uses it: Logitech -> only Logitech mice. PixArt -> almost every other brand.
• Naming: Logitech number = DPI. PixArt number = model code.
• Focus: Logitech -> battery efficiency. PixArt -> performance at every price.
• Upgrades: Logitech sometimes via software. PixArt -> new chip each generation.

~ like: Logitech = Apple (own chip, own products). PixArt = Qualcomm (sells chips to everyone).

10. Two sensors in one mouse?

People say 'dual sensor' for 3 different ideas:

• Type 1: 2 full sensors, front + back. Compare how much each moved -> the computer knows if you ROTATED. Used in research (some built with Arduino + 3D printer).~ like: 2 people at the front + back of a boat. Same move = straight. Different move = the boat turned.
• Type 2: main sensor + a 2nd sensor that measures lift height (down to 0.5mm). Stops the cursor skipping when you lift + land.e.g. SteelSeries Rival 600. Razer tried dual sensors back in the early 2010s too.~ like: one eye watches the road, the other watches how high you jumped.
• Type 3: ONE sensor with two sensing areas inside. Better tracking when you lift or tilt.e.g. Logitech HERO 2 ('Dynamic Spot Edge Detection', dual-array) + Ninjutso AimNinja 2 Pro ('dual optical engine').

How is it possible? The MCU (brain) gets data from both parts and combines it. Brands don't publish the inside details - just look for the BENEFIT it claims.

11. Sensor position

• Where the sensor sits changes how the cursor reacts when you rotate or flick with fingers/wrist.
• No 'correct' spot - it's personal preference, but worth checking before you buy.

e.g. G-Wolves Lycan advertises a forward sensor position. PAW3955 mice can also move a 'virtual' sensor centre in software.

12. How to test a sensor in your first week

• CPI deviation: set 800 DPI, move exactly 10 cm along a ruler, compare cursor distance with a 2nd trusted mouse. Big difference = deviation.
• LOD test: stack sheets of paper under the mouse, add one at a time, note when tracking stops.
• Glass test: try it on a glasspad - jitter? spin-outs? (AimNinja 2 Pro + PAW3950 claim better glass tracking).
• Polling test: use a polling rate checker + MouseTester to see if 1K/4K/8K is stable.
• Battery test: if wireless: test battery at 1K AND 8K.

-> Same test setup every time (same pad, same skates, same DPI) = you'll actually know if it's good.

(specs of older sensors are approximate - double check on eloshapes.com or sensor.fyi before trusting the numbers)

Remember!!

Don't get fooled by 42,000 DPI on the box. Look at the sensor NAME + where it sits on the ladder.

Real upgrades = lower LOD, better battery, glass tracking, stability at high polling.

Never compare brands by the number - compare by GENERATION.