KVM Switches - Buying Guide

A KVM (Keyboard, Video, Mouse) switch lets you control multiple computers from one set of peripherals. But choosing the wrong KVM leads to frustration: flickering displays, failed EDID detection, or peripherals that stop working after switching. This guide breaks down what matters and compares two popular models representing the DisplayPort vs HDMI divide.

What to Look for in a KVM Switch

1. Video Interface and Bandwidth

The most critical spec—determines max resolution and refresh rate:

Why DisplayPort costs more:

• Higher bandwidth for same generation (DP 1.4 > HDMI 2.0)
• Locking connectors reduce signal issues
• Better multi-monitor support (MST)

2. Number of Ports

Input computers vs output displays:

• 2×2: 2 computers, 2 monitors (most common)
• 4×2: 4 computers, 2 monitors (small office/lab)
• 2×1: 2 computers, 1 monitor (budget/single-display)

Critical distinction: "2 port KVM" is ambiguous—clarify if it's 2 computers or 2 monitors.

3. USB Peripheral Support

USB version determines peripheral compatibility:

• USB 2.0: Keyboard, mouse, basic peripherals (480 Mbps)
• USB 3.0/3.2 Gen 1: External drives, webcams (5 Gbps)
• USB 3.2 Gen 2: High-speed storage, capture cards (10 Gbps)

Powered vs unpowered USB:

• Some KVMs provide no USB power when inactive computer is selected
• Look for "USB charging support" if you need peripherals powered 24/7

4. Audio Switching

Not all KVMs switch audio:

• No audio: Video/USB only—use separate audio switcher
• 3.5mm audio: Headphone/mic passthrough
• HDMI audio extraction: Separate audio out from HDMI signal

For recording studios: Prefer HDMI audio extraction or dedicated audio routing over 3.5mm passthrough (better isolation).

5. EDID Management

EDID (Extended Display Identification Data) tells computers what resolutions/refresh rates the monitor supports.

Poor EDID handling causes:

• Blank screens after switching
• Resolution resets to 1024×768
• Windows repositioning on every switch

EDID emulation makes computers think monitor is always connected, preventing re-detection.

What to look for: "EDID emulation" or "EDID learning" in specs.

6. Switching Methods

• Hotkey: Keyboard shortcut (e.g., Scroll Lock + Scroll Lock + 1)
• Button: Physical button on KVM (most reliable)
• Remote: Wired remote switch (useful for under-desk mounting)
• Software: App-based switching (rare, requires USB driver)

Best practice: Button + hotkey combo for flexibility.

Product Comparison: HDMI vs DisplayPort KVM

Model 1: HDMI 2.0 Budget KVM

TESmart 2×2 HDMI KVM Switch↗

Specs:

• Video: HDMI 2.0—4K @ 60Hz (3840×2160)
• USB: USB 3.0 (5 Gbps)—4× USB 3.0 ports
• Audio: 3.5mm audio in/out
• Switching: Button + IR remote
• EDID: EDID emulator (claims to prevent display re-detection)
• Power: External 12V adapter
• Price: ~$160-$180

Pros:

• ✅ Affordable for dual-monitor setup
• ✅ HDMI cables widely available and cheap
• ✅ USB 3.0 sufficient for webcam, external drives
• ✅ Audio switching included (rare at this price)

Cons:

• ❌ HDMI 2.0 caps at 4K @ 60Hz—no high-refresh gaming
• ❌ No HDCP 2.2 mentioned—may fail with 4K streaming content
• ❌ EDID emulation quality unknown (check reviews for blank screen complaints)
• ❌ USB 3.0 may not power high-draw devices (external SSDs with multiple partitions)

Best for:

• Office productivity (1440p or 4K @ 60Hz)
• Dual-PC streaming setup (gaming PC + streaming PC)
• Users with HDMI-only monitors

Not ideal for:

• Competitive gaming (144Hz+ required)
• 4K Blu-ray playback (HDCP 2.2 uncertain)
• DisplayPort-only GPUs (requires active adapters)

Model 2: DisplayPort 1.4 High-End KVM

TESmart 2×2 DisplayPort 1.4 KVM Switch↗

Specs:

• Video: DisplayPort 1.4—4K @ 144Hz (with DSC), 8K @ 30Hz
• USB: USB 3.0 (5 Gbps)—4× USB 3.0 ports
• Audio: 3.5mm audio in/out + L/R audio out
• Switching: Button + hotkey (Scroll Lock × 2)
• EDID: EDID emulator with manual copy mode
• Power: External 12V adapter
• Price: ~$220-$250

Pros:

• ✅ DisplayPort 1.4 supports 4K @ 144Hz (DSC required)
• ✅ Better EDID management—manual copy from real monitor
• ✅ Locking DP connectors reduce accidental disconnections
• ✅ Dual audio outputs (3.5mm + L/R RCA)
• ✅ Hotkey switching (no need to reach for button)

Cons:

• ❌ More expensive ($60-$90 premium over HDMI model)
• ❌ Requires DisplayPort cables (slightly more expensive than HDMI)
• ❌ Still USB 3.0, not 3.2 Gen 2 (10 Gbps)
• ❌ DSC support depends on monitor—not all 4K @ 144Hz monitors include DSC

Best for:

• High-refresh gaming (1440p @ 144Hz, 4K @ 120Hz)
• Multi-monitor workstations (better MST support)
• Users with DisplayPort GPUs
• Environments where cables might get bumped (locking connectors)

Not ideal for:

• Budget-conscious users okay with 60Hz
• Game consoles (PS5/Xbox only output HDMI)
• Users with HDMI-only monitors (requires adapters)

Side-by-Side Comparison

Which Should You Buy?

Choose the HDMI KVM if:

• ✅ You use 60Hz displays (1080p or 4K)
• ✅ Budget is tight
• ✅ You need game console compatibility (PS5/Xbox)
• ✅ Your GPUs have HDMI outputs
• ✅ You don't need high-refresh gaming

Example use case: Office worker switching between work laptop and personal desktop, both running 4K @ 60Hz monitors.

Choose the DisplayPort KVM if:

• ✅ You game at 144Hz or higher
• ✅ You have DisplayPort-equipped GPUs (most modern gaming GPUs)
• ✅ You value locking connectors for stability
• ✅ You plan to upgrade to higher refresh rates
• ✅ You use color-critical applications (better color space support)

Example use case: Gamer switching between gaming PC and work PC, using 1440p @ 165Hz monitors.

Alternative Options

If You Need Higher USB Speeds

Level1Techs 2×1 DisplayPort 1.4 KVM↗

• USB 3.2 Gen 2 (10 Gbps)—supports high-speed capture cards
• Price: ~$400 (2× HDMI KVM cost)
• Trade-off: Single vendor, longer lead times

If You Need HDMI 2.1 (Console Gaming)

ATEN CS1922M HDMI 2.1 KVM↗

• 4K @ 120Hz for PS5/Xbox Series X
• HDMI 2.1 VRR support
• Price: ~$250-$300

If You Need 4+ Computers

TESmart 4×2 HDMI KVM↗

• 4 computers, 2 monitors
• HDMI 2.0
• ~$220

Installation Tips

1. Cable Quality Matters

• HDMI: Use "Premium High Speed" certified cables for 4K @ 60Hz
• DisplayPort: Use VESA-certified DP 1.4 cables
• Avoid long runs: <6 feet for DP, <15 feet for HDMI

2. EDID Configuration

On first setup:

1. Connect monitor to KVM
2. Connect both computers
3. Power on primary computer first
4. Let KVM "learn" EDID from monitor
5. Switch to second computer—if resolution is wrong, manually copy EDID (consult manual)

3. USB Power Management

Disable USB selective suspend in Windows:

• Control Panel → Power Options → Advanced → USB Settings → Disable selective suspend
• Prevents USB devices from sleeping when switching

4. Audio Routing

If using 3.5mm audio:

• Set computer audio output to "Line Out" or "Speakers" (not "Monitor audio")
• KVM's 3.5mm passthrough is analog—don't expect HDMI audio extraction unless explicitly stated

5. Hotkey Conflicts

Some applications capture Scroll Lock:

• Excel, terminal emulators
• Workaround: Use button switching or remap hotkey (if KVM supports it)

Common Issues

"Monitor Flickers When Switching"

Cause: EDID re-negotiation

• Solution: Enable EDID emulation. If already enabled, manually copy EDID from monitor.

"USB Devices Stop Working After Switch"

Cause: KVM cuts power to inactive computer's USB ports

• Solution: Use powered USB hub between KVM and peripherals, or choose KVM with "USB charging support."

"One Computer Shows Lower Resolution"

Cause: EDID mismatch—computer doesn't see correct monitor capabilities

• Solution: Force resolution in OS display settings, or use EDID override tool.

"Audio Crackles or Pops"

Cause: Ground loop between computers

• Solution: Use ground loop isolator on 3.5mm audio connection, or switch to optical audio (if available).

Final Recommendation

For most users: TESmart DisplayPort KVM is the better investment.

• $60 premium buys future-proofing for high-refresh monitors
• Locking connectors reduce flakiness
• DisplayPort is the PC standard—better GPU support

Save money with HDMI KVM only if:

• You're certain you'll never exceed 60Hz
• You need console compatibility
• Your monitors don't have DisplayPort inputs

Spend more on Level1Techs KVM if:

• You need 10 Gbps USB (capture cards, high-speed storage)
• You're a professional who can't tolerate switching issues
• You want best-in-class EDID management

KVM switches are a "buy once, cry once" purchase—spending extra for DisplayPort or better USB saves headaches later.