SmartAVI

SmartAVI SM-UHN-4D-S

Expert rating8.2 / 10

Port Count:: 4
Video Standard:: HDMI (dual-head)
Max Resolution:: 4K@60Hz per head

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Manufacturer: SmartAVI Last updated: 2026-10-09

SmartAVI SM-UHN-4D-S Review

SmartAVI SM-UHN-4D-S is a 4-port dual-head HDMI KVM switch with 4K at 60 Hz per head, 3 USB 2.0 hub ports, audio, and front-panel pushbutton and hotkey switching.

The SM-UHN-4D-S lets one keyboard, mouse and two HDMI monitors control four computers. Each head supports up to 3840x2160 at 60 Hz, so both screens keep 4K detail while you switch between machines, and switching works from the front panel or by hotkey. It has 3 USB 2.0 hub ports and audio support. The limits are HDMI only, so DisplayPort sources need adapters, USB 2.0 speed on the hub, and a cap of two displays per computer.

Full 4K60 on Both Heads

Many dual-head switches cap out at 30Hz or 1080p on the second display; the SM-UHN-4D-S keeps both HDMI heads at a full 4K@60Hz, which matters for video editors and CAD users running matched high-resolution monitors.

Comparison to Alternatives

It's SmartAVI's HDMI-native counterpart to the SM-DPN-4D-S in this same batch, which does the identical job over DisplayPort. Against ATEN's CS1944DP, the SM-UHN-4D-S trades DisplayPort for HDMI and true dual-head support, better suited to HDMI-first creative workstations.

Our verdict

Reviewed by Burooj Alam. Rated by us, not by users.

Expert rating8.2 / 10

One of the stronger dual-head 4K60 HDMI options in this price range; skip it if your monitors are DisplayPort.

Best for

Dual-monitor HDMI workstations
Video editors needing full 4K60 on both heads
Engineers switching four HDMI systems

Not for

DisplayPort-native monitor setups
Single-monitor desks
Budget single-head switching

Specifications

What these specs mean

Capability Score

5.3/10

How much this switch can do compared with other desk KVM switches, rated from its specifications.

Identity

Brand	SmartAVI
Model Number	SM-UHN-4D-S
Switching Method	Front-panel pushbutton + hotkey

Topology

Computers Supported	4 computers
Displays Per Computer	2 displays
KVM Segment	Desk

Video & Features

Video Standard	HDMI (dual-head)
Max Resolution	4K@60Hz per head
USB Hub Ports	3
Audio Support	Yes

Per display capability

Max Resolution Single Display	3840x2160
Max Refresh At Max Resolution	60 Hz
Max Refresh At 4K	60 Hz

USB peripheral switching

USB Switching Speed	USB 2.0

Switching control

Hotkey Switching	Yes

In the box and price

Price	674.25 USD

FAQs

What are the key specifications of the SmartAVI SM-UHN-4D-S (4-Port Dual-Head Ultra-HD HDMI KVM Switch)?

Key specs for the SmartAVI SM-UHN-4D-S: Max Resolution 4K@60Hz per head, Max Resolution Per Display 3840x2160, Max Refresh At Max Resolution 60 Hz, Audio Support Yes, Switching Method Front-panel pushbutton + hotkey, Video Standard HDMI (dual-head).

Who is the SmartAVI SM-UHN-4D-S (4-Port Dual-Head Ultra-HD HDMI KVM Switch) best suited to?

Best suited to: Dual-monitor HDMI workstations; Video editors needing full 4K60 on both heads; Engineers switching four HDMI systems.

What are the drawbacks of the SmartAVI SM-UHN-4D-S (4-Port Dual-Head Ultra-HD HDMI KVM Switch)?

Not the best fit for: DisplayPort-native monitor setups; Single-monitor desks; Budget single-head switching.