The Swedish Chefs at Mionix have a history of cooking up good gaming mice, and the Castor is another fine morsel form their kitchen. Or, as possibly the best-known Swedish Chef in America might say, “Yer der shmer dor her der foomty, der shoopin flerpity dur.”
Muppet or not, he’s right. The Castor is a great gaming mouse.
Feature highlights

One of the more interesting features of the Castor is (believe it or not) its shape. While it doesn’t deviate much from typical gaming mouse shapes, its subtleties make it a little more comfortable than many competitors. The Castor has a steeper slope at the front and subtle outward flares on the sides.
The combination creates a very comfortable mouse, especially for palm and fingertip grips. It also makes it easier to pick up the mouse if crash into the edge of your mouse mat.
The Mionix Castor is also a little smaller and a bit ‘daintier’ than similar mice from Razer and Logitech, which makes it an excellent option if you don’t have big banana hands or just prefer a smaller mouse in general.
Mionix Castor features and specifications

- 32bit ARM Processor running at 32Mhz
- Sensor: PMW – 3310 gaming grade IR-LED optical sensor up to 10,000 DPI
- MAX tracking speed of at least 5.45m/sec (215 IPS)
- No positive or negative hardware acceleration
- Adjustable Lift off Distance
- Right handed ergonomic design
- Soft touch rubber coating
- 6 fully programmable buttons
- 3 DPI settings
- 2 integrated LEDs (scroll wheel and logo)
- Up to 16.8 Million LED color options with color shift, Solid, Blinking, Pulsating and Breathing effects
- 128 kb built-in memory
Software Features
- Up to 5 Profiles saved to the in-built memory
- Adjustable X / Y Axis
- Polling rate adjustable: 250/500/750/1000Hz
- Live record macro manager
- Angle Snapping adjustable in 15 steps
- Angle Tuning adjustable from -30 to 30 degrees
- LOD Calibration tool
- S.Q.A.T™ – Surface Quality Analyzer Tool
- Lift-off distance (LOD) Calibration feature
The Castor is covered entirely in soft-touch rubber, with the thumb buttons surrounded by a lightly textured rubber surface. All in all, I found it to be a very comfortable mouse—slightly more so than some of my favorite Logitech designs like the G502, or Razer’s more rounded Mamba TE (a personal favorite).

The Castor is designed to appeal to the broadest range of mouse grips—palm up, fingertip grip, claw grip, etc. I tend to use more of a claw-like grip mixed with palm-up, and it works well for my grip style. I’m not sure if I like it quite as much as the Mionix’s NAOS series of mice, but at this point it’s a close second to the NAOS.
The thumb buttons are a bit ‘dainty’ and light for my taste—I tend to prefer them larger like those on the Razer DeathAdder (also a personal favorite, and one of Razer’s most popular mice).
The Castor’s lighting is understated, relegated to the scroll wheel and the glowing cosmic athletic cup that is the Mionix logo on the top-back of the mouse. The scroll wheel has low, soft ridges and it isn’t as stiff as I prefer for gaming. It provides a smooth, loose ride that is adequate for gaming and excels at Web surfing.
Performance

The Mionix Castor’s primary buttons all deliver solid, tactile response, although where the Castor truly shines is in comfort arguably one of the most important features for a gaming mouse, albeit a highly subjective one. But if you tend to find Razer and Logitech gaming mice a bit too large for your hand, definitely check out the Castor.
The Mionix software is streamlined and efficient. It doesn’t offer the breadth of features found in some gaming mouse software (I’m looking at you, Roccat), but it delivers all the core features common to most gaming mice, and does it with a simple, intuitive interface.
You can assign 3 different DPI levels, change the color of the LED lighting, and create and assign macros. You can adjust scroll speed, acceleration, and click speed, and there’s also a surface analyzer. Based on its surface analyzer, the Castor definitely seemed to “like” or perform better on a slick surface (my desk) as opposed to a fabric mouse mat (my Razer Goliathus).
Mionix software is very lightweight and provides the features you expect, providing a good overall balance between features and ease-of use. The Castor supports 3 DPI settings, adjustable in 50DPI increments from 50 to 10,000DPI. You can easily assign macros (single or multi-key), and the macro editor is more flexible than it first appears. Once a macro is recorded, you can still edit the macro by right-clicking in its window, easily adding additional strokes, delays, etc.
Unfortunately, the software doesn’t have the decency to actually install—you just download it, extract it, and run the executable. It’s a bit clumsy as far as installation is concerned.
Overall: 8/10 – Recommended
The Mionix Castor shines in comfort and is an excellent all around gaming mouse and an outstanding contender in the ~$75-$90 price point. I think the scroll wheel could be improved slightly (from a gaming perspective), and the software could use some refinement, but otherwise the Castor is a solid recommendation–especially if you have smaller hands or prefer smaller mice.
Compare it to the likes of the Razer Mamba TE.