KVM switch
A device that lets two or more computers share a keyboard, display and mouse.
- Why it matters
- It must switch every video signal and USB device your desk needs.
- Do most people need to care?
- Care if you want to share monitors or peripherals between computers.
Resolution
The number of pixels in the picture, such as 2560×1440 or 3840×2160 (4K).
- Why it matters
- More pixels require more video bandwidth, especially at high refresh rates.
- Do most people need to care?
- Care about the exact resolution of your monitor, not just labels such as 4K or 5K.
Refresh rate
How many times the screen updates each second, measured in hertz (Hz).
- Why it matters
- 60Hz is normal for office work. 120Hz, 144Hz and 240Hz make motion smoother but require much more bandwidth.
- Do most people need to care?
- Most office users can choose 60Hz. Gamers and motion-sensitive users should check the monitor’s intended rate.
HDMI and DisplayPort versions
HDMI and DisplayPort are video connections. Newer versions can usually carry more pixels, higher refresh rates and more display features.
- Why it matters
- A KVM, computer, adapter, cable and monitor must all support the required signal. One older link can reduce the result.
- Do most people need to care?
- Care for 4K above 60Hz, ultrawide displays, HDR or variable refresh. For ordinary 4K60, the exact version is less likely to be decisive.
USB 2.0 and USB 3.x bandwidth
USB 3.x moves far more data than USB 2.0. The exact USB 3.x generation may provide 5Gbps, 10Gbps or more.
- Why it matters
- A keyboard and mouse need very little bandwidth. A high-resolution webcam, capture device or external drive may need USB 3.x.
- Do most people need to care?
- Ignore high-speed USB if you only share a keyboard, mouse and basic audio device.
USB-C
A small reversible connector. It can carry data, power and sometimes video, but the connector shape alone does not guarantee which features are present.
- Why it matters
- A USB-C KVM needs the computer port to support video output, data and, if required, charging.
- Do most people need to care?
- Care whenever you want a one-cable laptop connection. Check the computer specification, not just the USB-C logo.
Thunderbolt
A high-bandwidth connection that uses the USB-C connector and can carry video, data and power.
- Why it matters
- Thunderbolt can support more capable docks and multi-display arrangements than basic USB-C, but exact computer and display support still varies.
- Do most people need to care?
- Care if the KVM or your displays specifically require Thunderbolt. It is not interchangeable with every USB-C port.
Power Delivery (PD)
USB Power Delivery is the charging power supplied through USB-C, measured in watts.
- Why it matters
- A laptop may charge slowly or lose battery under load if the KVM supplies less power than its normal charger.
- Do most people need to care?
- Care if you want one cable to handle both the KVM connection and laptop charging. Ignore it if you will use the laptop charger separately.
EDID emulation
EDID is the monitor information a computer uses to learn its supported resolution and display layout. Emulation keeps that information available while the computer is not selected.
- Why it matters
- Without it, displays may briefly reconnect, windows may move, or resolution may change when you switch computers.
- Do most people need to care?
- It is useful for multi-monitor desks and carefully arranged windows. You can ignore it if a short reconnect would not bother you.
Multi-Stream Transport (MST)
MST sends more than one display signal through one DisplayPort or USB-C connection.
- Why it matters
- It can give Windows laptops two extended displays through one cable. Most Macs do not use ordinary MST to create two independent extended displays, so the screens may mirror each other.
- Do most people need to care?
- Windows laptop users may need it. Mac users should treat any dual-display MST KVM as a warning unless the manufacturer documents a different native route.
Extended vs mirrored displays
Extended displays provide separate desktop space on each monitor. Mirrored displays show the same picture on both.
- Why it matters
- A dual-monitor KVM is only useful for most work if the computer can supply two independent display signals.
- Do most people need to care?
- Care if you expect to move different windows between two monitors, especially on a Mac or a single-cable laptop dock.
High dynamic range (HDR)
HDR can show a wider range of brightness and colour than standard dynamic range on compatible content and displays.
- Why it matters
- A KVM or adapter that cannot pass HDR may still show a normal picture, but without the HDR effect.
- Do most people need to care?
- Care for HDR games, films or colour work. Ignore it for ordinary office applications.
Variable refresh rate (VRR)
VRR lets the monitor adjust its refresh rate to match changing game frame rates.
- Why it matters
- It reduces screen tearing and judder. A KVM can pass the picture while still blocking or failing to confirm VRR.
- Do most people need to care?
- Care mainly for gaming. Office and general productivity users can normally ignore it.
G-Sync and FreeSync
Nvidia G-Sync and AMD FreeSync are common variable-refresh technologies.
- Why it matters
- The graphics card, monitor, connection and KVM must preserve a compatible variable-refresh path.
- Do most people need to care?
- Care if you already use one of these features for gaming. Otherwise use the general VRR option only if needed.
Display Stream Compression (DSC)
DSC compresses a very high-bandwidth display signal so it fits through a connection such as DisplayPort 1.4 or HDMI 2.1.
- Why it matters
- It can enable 4K144, 4K240 and demanding ultrawide modes. Every device in the chain must handle the same DSC mode.
- Do most people need to care?
- Care for very high refresh rates or large ultrawides. At 4K60, you can usually ignore it.
Mac display support
Each Mac model has a maximum number of external displays and supported resolution and refresh combinations.
- Why it matters
- A KVM cannot create display outputs the Mac does not support. Adapters and docks can also change the route.
- Do most people need to care?
- Always care when using more than one external Mac display or an unusually high resolution or refresh rate.