Want a great PC mouse? Understand these terms

Many people think of the mouse as one of the most basic PC peripherals. Point, click, and that's it. But modern mice have come a long way, and if you're looking for a more advanced mouse, you may be confused by some of the marketing terminology.

Below, we'll give quick breakdowns of some of the most common terms you'll see when looking for a feature-packed mouse. If you're paying $50 (or even $150 or more) for a mouse, you should know exactly what you're getting.

Optical sensor

Modern mice use optical sensors, which leverage LEDs, complementary metal oxide semiconductor (CMOS) image sensors (like in a camera), and a digital signal processor (DSP) to convert your arm movements into pointer movements. The DSP, as explained by How Stuff Works, "is able to detect patterns in the images and see how those patterns have moved since the previous image. Based on the change in patterns over a sequence of images, the DSP determines how far the mouse has moved and sends the corresponding coordinates to the computer." A bit less common are laser sensors, like the Logitech Darkfield sensor used in Logitech MX Master 3.

The MX Master 3 uses Logitech's proprietary Darkfield laser sensor.

Credit: Scharon Harding

An optical or laser sensor also means you don't need a mousepad for the mouse to work well. Mice makers, like those behind the MX Master 3, sometimes brag about this as if it were an exclusive feature. But even a cheaper optical or laser mouse (this $20 Microsoft mouse we just pulled out of a dusty closet, for example) should work sans mousepad.

Yes, even this basic thing works without a mousepad. 

Credit: Scharon Harding

Just because you can use a mouse without a mousepad doesn't mean you'll actually want to. Skipping a mousepad can make movements feel and sound scratchy, especially if the mouse lacks feet on its underside to help it glide more smoothly. And working on some surfaces feels better than others.

Some brands, including Logitech and Razer, make their own sensors. PixArt, meanwhile, is the most common third-party brand for optical sensors.

But not all advanced mouse sensors are made equal. If you're going to invest money in a good PC mouse, it's a good idea to check out the sensor's performance specs.

DPI or CPI

Dots per inch (DPI) and counts per inch (CPI) are used interchangeably around the mouse world. What's the difference? Basically, DPI came from the print world and is taken from the display's perspective, while CPI comes from the mouse sensor's perspective. Either way, the acronyms are indicative of the mouse's sensitivity, or how many pixels your pointer will move when you physically move the mouse.

When using a mouse with a low DPI or PCI setting, the cursor will move very slowly across the screen. A mouse with a high CPI setting will move much more rapidly across the screen with the same movement. Without getting too technical, for every inch a mouse with 1,000 CPI moves, your cursor will (generally) move 1,000 pixels. (That's according to PC gaming peripherals maker SteelSeries.) Many high-end mice let you specify the mouse's CPI. Their software may let you use a slider or enter a specific number or numbers. Some mice also have a dedicated button, called a CPI or DPI switch, for toggling across saved CPI or DPI settings. And there are some gaming mice with a sniper button, or a button that instantly drops the mouse's CPI when held down, in order to home in on a target, like in a first-person shooter.

Low CPIs aren't just about headshots though. Some users may prefer a low CPI for precise movements for general gaming. A low CPI can also come in handy for creative work, like when you're trying to get the right color down to the last pixel.

A high CPI, on the other hand, can accommodate a large or high-resolution PC monitor. A high CPI also lets you zip across your favorite games or apps with minimal physical effort. Some mice can, with the help of their software, achieve CPI counts as high as 36,000, like the upcoming ROG Chakram X gaming mouse that Asus announced earlier this month. But that's an extreme spec.

The upcoming Asus ROG Chakram X has a CPI of up to 36,000.

Credit: Asus

You can find plenty of good mice for gaming or productivity with CPI ranges of about 200–3,000. Logitech's MX Master 3 is one of the most advanced productivity mice, and it's specced for 200–4,000 CPI. But for users who want their pointer to zip across the screen with just a brush of the mouse, there are options, too.

IPS

IPS stands for "inches per second" and refers to the maximum velocity that the mouse sensor supports. It tells you how rapidly you can move your mouse before the device is unable to track movements accurately. If you tend to move your rat around very quickly, such as for playing games, you'll want something with a higher IPS spec. But while some high-end productivity mice offer a CPI / DPI spec, IPS is rarely mentioned outside of gaming mice.

We've seen gaming mice with max velocities of up to 650 IPS. But most won't need such an extreme IPS, and sensor performance isn't just about a single spec.

For hardcore gamers, CPI, IPS, and acceleration (which we'll get into next) are all important. Each number plays a role in how reliable the mouse's sensor is and how well the mouse's on-screen movement and action lines up with your physical input.

Acceleration

A mouse sensor's acceleration spec tells you how much inertial force your mouse can handle while still tracking accurately. Go past that capability, and you can expect issues like shakiness. Today's mice are specced for up to 50 g, and greater numbers are important if you tend to flick or quickly swipe your mouse.

Here's a helpful simile on acceleration from SteelSeries: "If the top speed of that Bugatti is like a mouse's IPS rating, then the Bugatti accelerating 0-60 mph in under 2.5 seconds is like the G rating of your gaming mouse."

Sensor acceleration is not to be confused with mouse acceleration. Mouse acceleration is a feature that changes pointer sensitivity based on how fast you're actively moving the mouse. Some mouse apps let you turn this off, and you can also toggle it in Windows 11 and Windows 10, where it's called "Enhanced pointer precision."

Polling rate

While mouse makers, especially those focused on gaming, have been upping CPI specs for years, increasing the polling rate of mice is a trend that really kicked off in 2021. That's when multiple brands, including some mainstream ones, started releasing mice with polling rates greater than the typical 1,000 Hz. Now, there are numerous choices with polling rates as high as 8,000 Hz.

A mouse's polling rate tells you the max number of times the mouse may send a location report to your computer per second. A 1,000 Hz mouse does so 1,000 times per second. That results in an input delay (the amount of time from when you move your mouse or press a button to when that action appears on screen) of as low as 1 ms. That figure comes from 1 second divided by 1,000 reports for a quotient of 0.001 second, or 1 ms. Today, you can find mice with 8,000 Hz polling rates, which reduces the minimum input delay from 1 ms to 0.125 ms (1 second divided by 8,000 reports equals .000125 second).

High-polling mice promise to offer smoother tracking than 1,000 Hz ones, and we've seen 8,000 Hz mice that can create a visibly more consistent trail of mouse pointers, for example, when moving the peripheral around rapidly on a decently powered gaming system. These advanced mice are best reserved for gamers who have a powerful GPU and CPU and a monitor with a high refresh rate. This way, you can push the mouse to its maximum potential and have a better chance of noticing the difference with your own eyes.

And even though 1,000 Hz is the standard mouse polling rate these days, some mice also have software that lets you lower the polling rate for USB compatibility reasons or to conserve CPU resources. The 8,000 Hz Razer Viper 8KHz and the 1,000 Hz Razer Basilisk V3 are examples. Their Razer Synapse app has a dropdown menu letting you quickly select a 500 or even 125 Hz polling rate.

2.4 GHz

You'll find "2.4 GHz" when looking at wireless mice. It basically means the mouse connects wirelessly by inserting a dongle into your computer's USB port. That differs from Bluetooth, which doesn't require any ports for its wireless connection.

Both wireless options use the 2.4 GHz radio frequency, but when shopping for a mouse, you'll see the term 2.4 GHz used to refer to a mouse's dongle connection. While Bluetooth is a standardized use of 2.4 GHz that divides the band into 40 channels for congestion-avoiding frequency hopping, 2.4 GHz dongles can work in various ways. This allows brands to make their own 2.4 GHz dongle tech—and each company can claim its product is the best, of course.

A dongle connection is generally expected to offer less lag than its Bluetooth counterpart. That's because Bluetooth has a max polling rate of 133 Hz, which results in a minimum delay of 7.5 ms (1 second divided by 133 reports is 0.0075 second). We just talked about how some people are using 8,000 Hz mice with a purported 0.125 ms delay, so that's obviously a turnoff for some serious gamers. Meanwhile, there are gaming vendors, such as Logitech with its Lightspeed, that claim their dongle technology has a delay of just 1 ms. And you can use a dongle mouse from farther away from your computer if it comes with a wireless extender. This is a piece with one USB port for attaching a cable that connects to your PC and another USB port for inserting the mouse's dongle. By using the cable, you can bring the dongle physically closer to where its mouse is.

Some gamers won't even touch a wireless mouse because of perceived lag, as well as the potential for dropped connections. Other serious gamers will use a wireless mouse—but only with a dongle. And we've seen plenty of casual gamers make do with a Bluetooth wireless mouse without complaint.

Onboard memory

If you use your mouse with multiple devices, take note. Onboard memory is as it sounds: it gives a mouse the ability to store your preferred settings—like CPI settings, key mappings, and RGB preferences—onboard, or on the mouse itself. That means you can connect the mouse to another computer, and the mouse will remember your settings without you having to download the mouse's software and reprogram it again.

Some mice let you store multiple onboard profiles. That means you can easily swap between different profiles for gaming versus work, for example, or different settings for different games. But sometimes a mouse's more advanced features, like launching a program when pushing a button or RGB settings, won't carry over to a new PC without downloading the mouse's software, even with onboard memory.

Palm grip, claw grip, and fingertip grip

These are the three most popular ways to hold a mouse, and we often refer to them in mice reviews at Ars Technica. Some mice are better for particular grips, and this can be determined by testing or just by taking the vendor's word for it.

Palm grip.

Scharon Harding

Palm grip. Scharon Harding

Claw grip.

Scharon Harding

Claw grip. Scharon Harding

Fingertip grip.

Scharon Harding

Fingertip grip. Scharon Harding

Claw grip. Scharon Harding

Fingertip grip. Scharon Harding

As you can see in the gallery above, a palm grip sees your palm touching the back of the mouse, or its hump, while your wrist is on the desk. This is considered the most common grip; although, it's harder to do with smaller mice or ones with a shorter hump. Claw grips are just like palm grips, but your palm doesn't touch the mouse. And a fingertip grip is just like a claw grip, but your wrist doesn't touch the desk.