Surface Pro Pen Compatibility / Interoperability FAQ

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Many customers seem confused about which Surface Pen features work on which Surface devices. The table below summarizes compatibility between different pen generations and Surface device models. Pressure sensitivity, latency, initial activation force, and tilt functionality are detailed as well using best available information as of 2017/07/31.

Disclaimer: This information is subject to change if/when Microsoft releases additional details as some assumptions about the implementation are made based on n-Trig patent filings.

How to read the table:

  • 256, 1024, or 4096 indicates the number of pressure sensitivity levels available when using the pen and device model together. (256=8-bit, 1024=10-bit, 4096=12-bit.) In practice, many customers will not notice a difference in the pressure sensitivity given limited hand dexterity and the dynamic range compression/clamping side-effects of many software applications. The available pressure levels depends on a combination of the pen, digitizer hardware, and device drivers.
  • Tilt indicates that the Surface device has an accelerometer and the Pen incorporates some device enabling the Pen/Ink API to detect the angle of the pen with respect to the screen. According to n-Trig patent filings, this device could be an accelerometer, gyro, or a secondary radio emitter positioned such that the digitizer can infer the pen orientation. This allows software to change brush strokes on-the-fly based on the tilt of the pen. Even without the tilt feature, RF triangulation can enable the digitizer system to recognize gross orientation of the pen (right-handed use vs left-handed use for example) to optimize the tracking behavior. Assuming the user rests their palm on the screen, palm-rejection can also help optimize tracking behavior.
  • >21ms, >40ms, >55ms, >75ms, or >100ms indicates the minimum digitizer->screen latency. Real-world latency may be up to 50ms higher depending on the software being used, the refresh rate of the screen, and the timing of the pen event with respect to the refresh of the current frame. Assuming worst case at a 60Hz screen refresh rate, you can conservatively add 16.67ms (the time it takes to render one frame) to each of the quoted figures to get a more realistic latency. Device driver and software application updates can significantly alter the latency behavior making responsiveness better or worse.
  • 9g, 10g, 21g, 42g indicates the initial activation force (IAF) in grams which is the minimum amount of pressure applied to the tip of the pen to register as a stroke  on-screen. Less force is better for light strokes of the pen – but too little IAF can result in unwanted strokes. This is a crucial tuning factor for any pen/digitizer system. The ideal IAF is highly subjective depending on the artist. Typically Wacom designs have an IAF of 1-10 grams while n-Trig designs are on the order of 10-50 grams. With each generation of n-Trig pens, the IAF has decreased. To compare IAF across pen manufacturers, each pen design must be mounted and tested on the same test rig at a variety of angles since the response may be different in a vertical orientation compared to a natural writing angle depending on the mechanical implementation.
  • n/a indicates that the pen and device combination does not work.
Pen / Device Pro 1 Pro 2 Pro 3 3 Pro 4 Book Studio Laptop Pro 2017 Hub
Ver.1 Wacom 256
>100ms
~10g
1024
>100ms
~10g
n/a n/a n/a n/a n/a n/a n/a n/a
Ver.2 n-Trig n/a n/a 256
>75ms
~42g
256
>75ms
~42g
256
>40ms
~42g
256
>40ms
~42g
256
>40ms
~42g
256
>40ms
~42g
256
>21ms
~42g
n/a
Ver.3 n-Trig n/a n/a 256
>75ms
~21g
256
>75ms
~21g
1024
>40ms
~21g
1024
>40ms
~21g
1024
>40ms
~21g
1024
>40ms
~21g
1024
>21ms
~21g
n/a
Ver.4 n-Trig n/a n/a 256
>75ms
9g
256
>75ms
9g
1024*
>40ms
tilt*
9g
1024*
>40ms
tilt*
9g
1024*
>40ms
tilt*
9g
1024
>40ms
9g
4096
>21ms
tilt
9g
n/a
PPI n/a n/a n/a n/a n/a n/a n/a n/a n/a 1024 >55ms

*Ver.4 n-Trig tilt functionality and enhanced pressure sensitivity may be enabled on some older Surface models via driver/firmware updates in early 2018.

Which pens shipped with which device models?

  • Wacom Ver.1 pens shipped with the Surface Pro 1 and Surface Pro 2.
  • n-Trig Ver.2 pens shipped with the Surface Pro 3 and was an optional accessory for the Surface 3.
  • n-Trig Ver.3 pens shipped with the Surface Book, Surface Studio and Surface Pro 4 (except m3 model). It is an optional accessory for other models.
  • The n-Trig Ver.4 pen is an optional accessory designed for the 2017 Surface Pro but also works on older models.
  • The Surface Hub ships with two Surface Hub pens based on the Perceptive Pixel (PPI) digitizer technology.

Replaceable pen tips?

  • n-Trig Ver.2 pens has a replaceable tip. Replacement tips are available and may be swapped from other pen manufacturers.
  • n-Trig Ver.3/Ver.4 pens have swappable tips. Microsoft sells a 4-pack of tips each with a different writing feel.

Batteries?

  • Wacom Ver.1 pens use electromagnetic digitizers and need no batteries.
  • n-Trig Ver.2 pens are powered by a AAAA battery combined with two #319 (SR527SW) button cells.
  • n-Trig Ver.3/Ver.4 pens are powered by a single AAAA battery.
  • Surface Hub pens have non-replaceable rechargeable batteries and charge when docked on the Hub.

Buttons?

  • Wacom Ver.1 pens have 2 buttons
  • n-Trig Ver.2 pens have 3 buttons
  • n-Trig Ver.3/Ver.4 pens have 2 buttons plus “eraser”
  • Surface Hub pens have an “eraser” but no buttons

Clip?

References:

Did I miss anything? Please comment and I’ll add it to the article.

Edit: Changed Gen0-Gen3 terminology to Ver.1-Ver.4 to be consistent with Microsoft documentation – 2017/06/19

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3 thoughts on “Surface Pro Pen Compatibility / Interoperability FAQ

Add yours

  1. Despite what the patent says, there are no accelerometers or gyroscopes in any tilt-sensing pen technology (Apple, Wacom EMR, Microsoft). Apple uses additional sensors that are perpendicular to the tip of the pen and analyzes the shape of the signal on the digitizer. Wacom EMR analyzes the shape of the signal on the digitizer without any additional emitters. Microsoft (according to the patent) added more emitters to create an asymmetrical signal on the digitizer, which then lets it calculate 3D orientation. Not a single one uses accelerometers or gyroscopes.

    Liked by 1 person

    1. Thanks Jack. I misread the filing. I’ve updated the post accordingly to indicate n-Trig may be using one or more of these techniques. A secondary emitter makes a lot more sense given power consumption of an accelerometer/gyro package.

      Like

  2. So there’s no current evidence that the surface studio nor surface book performance base will be capable of the lowest latency features?

    Like

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