What you should know about the peripheral polling rate
You’re a passionate gamer. You’ve got a highly professional setup already, but the performance of your mouse lets you down. You have already made numerous adjustments, yet you continue to notice a significant delay between the input and what happens on the screen. There is one more variable, however, that you may not have thought about previously, but that can be decisive: the polling rate. Find out what the polling rate is exactly and what effect it can have on your gaming experience in our guide.
- What is the polling rate?
- What does a low polling rate mean?
- What does a high polling rate mean?
- What is the polling rate for a keyboard?
- How do I adjust the polling rate of a keyboard?
- What is the polling rate for a mouse?
- How do I check the polling rate of a mouse?
- What is the optimal sampling rate for a mouse?
- What is the relationship between the polling rate and the response time?
- How do I adjust the polling rate of my gaming mouse correctly?
- What is angle snapping?
- Why is a higher polling rate advantageous?
The polling rate is the rate at which inputs are captured by an input device. This rate determines how quickly a mouse or a keyboard sends information to the PC. At the same time, the PC is continually sending new inquiries to the input device. The more frequent these inquiries occur, the faster it is that movements or button inputs from the mouse or keyboard can be processed. If a fast response is required, a particularly high polling rate is required. These are measured in hertz (Hz). While the needs of most people who use their PC for surfing or office work are satisfied with an ordinary polling rate, gamers require a higher rate in order to secure decisive advantages in the game. The polling rate determines how frequently the PC reads information from the mouse or keyboard that has been held in a buffer. This means that at a polling rate of 125 Hz, say, the information is read 125 times per second. In other words, there is a delay of 8 ms between the physical movement of the mouse and the detection of the movement by the computer. In ordinary use this is not a problem, but it is certainly an issue for gamers.
A low polling rate means a very long response time. Thus there is a long delay between an action being taken and the result appearing on the screen. This can result in an input lag – in which there is a time delay between the mouse being moved or clicked and the effect appearing on the display.
A high polling rate means a very short response time. This ensures that far more accurate, better results can be achieved. This is why gamers prefer mice with a polling rate of at least 500 Hz and ideally 1000 Hz. When a high polling rate is selected, the response time is reduced right down to 2 milliseconds at 500 Hz and 1 millisecond at 1000 Hz.
The polling rate for a keyboard likewise specifies how often the keyboard data is read – that is, how often a check is made whether any keys have been pressed or released. If this is so, the characters are captured and processed immediately. To ensure that no character is lost in this process, a polling rate should be chosen that is well above the speed at which a person can type (number of characters per second). Keyboard polling rates are thus only really of interest to people who write often and above all fast, and to gamers.
Generally two possibilities exist, at least with modern keyboards. In many models the polling rate can be set directly on the keyboard itself, with various settings from 125 Hz through 250 Hz and up to 500 or 1000 Hz. The adjustment can often be made by means of a switch, though in some cases a special key combination must be pressed. Alternatively, some manufacturers allow the setting to be made within the keyboard software or driver.
For a mouse, the polling rate defines how often information is read by the system, and thus also how frequently that information is sent to the PC. The more frequently the computer reads the information, the more quickly it receives new input that it can process immediately. In addition to mouse movements, the clicking of mouse keys is collected as information.
If you don’t know the polling rate at which the mouse is operating, this can be checked quite easily with the appropriate tools. Normally the manufacturer also offers a software module designed for testing the mouse model concerned. Alternatively, many free tools are available that check the polling rate of a mouse, such as the Windows Mouse Rate Checker. This is a small simple program that captures mouse movements and gives an indication of the mouse polling rate. And if you don’t want to download software for this, online tools are also available.
There is no optimum sampling rate for a mouse in itself; the best rate is always a function of how the mouse is used. Without question, a high polling rate plays an important part for gamers. In a game, a difference of one millisecond can be decisive. Consequently, the optimum sampling rate for mice used for games is at least 500 Hz and ideally 1000 Hz. In general, wherever rapid mouse movements are important, the polling rate should be as high as possible. Meanwhile mice used for office tasks or general surfing can operate perfectly well at 125 Hz or 250 Hz. In such activities a millisecond is not significant.
The higher the polling rate, the lower the response time. The lower the polling rate, the higher the response time. The polling rate therefore determines the response time.
With a gaming mouse also, the polling rate is normally set either directly on the mouse itself, by means of a switch or particular button combination, or via the software or driver. Even where these mice usually support polling rates from 125 to 1000 Hz, a rate of at least 500 Hz is recommended. Gaming pros should select 1000 Hz. People who play at a lower than pro level, however, are unlikely to notice a difference between 500 and 1000 Hz. Meanwhile there are also other technical factors that are important for gaming with the mouse. These include DPI, LOD and IPS.
The DPI (dots per inch) parameter is an indication of the sensitivity of the mouse, in terms of the number of dots per inch it returns. The higher the DPI, the greater the sensitivity of the mouse. The sensitivity can be set in the Windows settings. Although a DPI value is not shown there, the ‘Pointer Options’ item allows you to set the speed of the mouse pointer. The bigger the bar is set, the higher the mouse sensitivity. This is experienced in a faster movement of the mouse pointer.
Lift-off distance or LOD specifies how far a mouse can be lifted off the surface (mouse pad, desk etc.) while continuing to function. Most models offer a LOD of 1.5 to 1.8 mm; the maximum possible distance is usually 2 cm. This value is important for gamers who often lift the mouse while playing. In such cases the LOD should be as low as possible. Players who don’t normally lift the mouse and do not play FPS games can also use models with a higher LOD.
IPS (inches per second) represents the maximum speed at which a mouse sensor is still capable of outputting correct values. For a mouse rated at 250 IPS, the maximum speed is about 6.35 meters per second. This means that a 250 IPS mouse is more than adequate.
This is the property of a mouse movement being oriented to a specific vector. With this function, rough or wobbly lines created by the mouse can be smoothed automatically. If the mouse is used to create a horizontal line, there are invariably deviations; this comes down to human imprecision. Where the mouse features angle snapping, however, the deviations are suppressed and the line is corrected to a specified vector, in this case a horizontal. While this can be a useful function for many activities, it can however be problematic in gaming. For this reason it can be disabled on most mice.
A higher polling rate is advantageous because it reduces the response time considerably. This means that mouse movements or clicks of mouse buttons reach the computer faster and can so be processed more rapidly. An important advantage in gaming, but also in many other fields.
Now you know enough to be able to adjust the polling rates of your mouse and keyboard so that the best gaming results are available to you from the moment you start your computer. Often it is only small adjustments that make a noticeable difference. From the moment that you buy a mouse or keyboard, you should check that it supports a high polling rate. In the best case the rate can be simply adjusted to suit your personal needs. For gaming in particular, the polling rate can be decisive, while for other PC activities its role is secondary.