Polling rate is likely one of the most prominently displayed details on any Hall effect keyboard, purely because the large numbers emphasize one of the most important aspects of these keyboards: Speed. Whether a keyboard has a 1,000- or 10,000-Hz polling rate, this number represents how many messages are sent from the keyboard to the PC every second. For example, a keyboard with 1,000-Hz polling will send 1000 messages every second. Most office equipment operates at 125 Hz. In high-performance gaming, a higher polling rate is almost always preferred, since more information being transferred reduces the chances of a movement or keypress not being recognized immediately. That said, 1,000 Hz is more than enough—you won’t really notice many benefits of going higher.
Software has also proven to be make-or-break with Hall effect keyboards. Nearly every HE keyboard relies on software to make adjustments and customizations, so this is a critical aspect of a good keyboard. In evaluating this, I consider ease-of-use, functionality, and the scope of customization. Software that makes customization difficult, has any stability issues, or uses a lot of processing power will just cause issues down the road.
Build quality is important for both obvious and less-obvious reasons. It’s important for a keyboard to feel good to type on and to have a rigid construction, but it also matters how good quality control is with switches and how well-tuned the stabilizers are. Because Hall effect keyboards rely on magnets and sensors to register keypresses, a misalignment of a magnet or sensor can cause keypresses to register at incorrect distances without any obvious tells, which can cause issues with your performance when gaming.
Actuation distance is typically measured in millimeters and indicates the distance a key has been pressed. Hall effect keyboards usually measure to a tenth of a millimeter, although sometimes they extend out to a hundredth of a millimeter. Most keyboards will measure this from the top resting position, at zero millimeters. The bottom-out distance, where the key is fully pressed, will typically sit between 3 and 4 millimeters. The distance between the top and bottom of the keypress is the travel distance, and the maximum travel distance possible is determined by the switches you’re using and the keyboard itself. If you have a switch with a 4-mm travel distance and a keyboard that only measures up to 3.5 mm, you will only be able to set the actuation distance to 3.5 mm at the lowest.