Vertiv SC940DVI-400 4-Port Secure Desktop KVM Switch
Overview
The Vertiv SC940DVI-400 is a 4-port secure desktop KVM switch from the Cybex SC900 series, purpose-built for environments where physical signal isolation between classified and unclassified systems is non-negotiable. If you're managing multiple security domains from a single workstation — government, defense contracting, financial compliance, or high-security operations centers — this is the class of switch that belongs on the desk, not a standard IT KVM. The SC940DVI-400 supports UHD 4K video at 30Hz over DVI-D connections, with compatibility for DVI-D to DVI-D or DVI-D to HDMI configurations, meaning it fits both legacy DVI workstations and modern HDMI displays without a converter pile on the desk.
Vertiv's Vertiv KVM and infrastructure portfolio covers everything from data center switching to desktop-level secure access — the Cybex SC900 line sits at the secure-desktop tier, designed for users who need hardware-enforced separation rather than software-based switching. If you're evaluating secure KVM switches for a multi-domain workstation environment, understanding the distinction between standard KVMs and secure (NIAP-evaluated) KVMs is the starting point — this product targets the latter use case.
Key Features
- 4 Independent Secure Ports: Four physically isolated computer connections let a single operator access up to four systems — each on a separate security domain — from one keyboard, video, and mouse setup. Hardware isolation means there is no electronic data path between connected systems, which is the fundamental requirement for cross-domain workstations in classified environments.
- UHD 4K Resolution at 30Hz: Supporting 3840×2160 at 30Hz means you're not downsampling to 1080p on a 4K display when switching between systems. For analysts working with GIS imagery, CAD, or high-density surveillance feeds, retaining full 4K fidelity across every port matters — a KVM that caps at 1080p or 1440p becomes the bottleneck the moment you upgrade your monitors.
- DVI-D to DVI-D and DVI-D to HDMI Video: The SC940DVI-400 handles both native DVI-D connections and DVI-D to HDMI conversion, giving you flexibility when your workstation outputs DVI but your display accepts HDMI. This dual-connection support reduces the need for passive adapters at each port, which can introduce signal degradation or compatibility headaches in a rack-dense setup.
- Compact Desktop Form Factor: At 1.7 inches in profile height, the SC940DVI-400 sits flat on a desk or mounts in a shallow space without consuming significant real estate. For operations desks where space is allocated to the inch, that low-profile chassis matters — you're not adding a 1U rack appliance footprint to a workstation environment.
- SC900 Series Secure Design: The Cybex SC900 family is engineered for secure desktop switching, incorporating hardware-based isolation features aligned with the requirements of multi-domain secure workstation deployments. This is not a consumer or standard enterprise KVM repurposed for secure environments — it's built from the ground up for that use case.
- Single-Operator Multi-Domain Access: Consolidating four systems under one keyboard and mouse eliminates the physical sprawl of separate peripherals per system. In high-security operator environments where desk layouts are standardized and audited, reducing peripheral count also reduces potential vectors and simplifies cable management.
Integration and Compatibility
The SC940DVI-400 connects via DVI-D on the computer side, supporting both straight DVI-D to DVI-D and DVI-D to HDMI video paths. Verify that your connected workstations output DVI-D (not DVI-A or DVI-I analog-only) before procurement — the DVI-D standard carries only digital signal, and analog-only DVI sources will not work. The 4K @30Hz ceiling is a hardware limit of the DVI-D interface itself; if your workflow requires 4K @60Hz, that requires DisplayPort or HDMI 2.0 switching hardware, not DVI. For KVM accessories and cabling, confirm cable lengths and DVI-D certification ratings appropriate for 4K signal integrity — longer runs can degrade 4K reliability even on a quality cable.
Integrators deploying this unit in a NIAP-regulated environment should verify current NIAP Product Compliant List (PCL) status for the SC940DVI-400 directly with Vertiv, as certification status can change independently of product availability. For organizations building out a secure KVM infrastructure, the SC900 series spans multiple port counts and video interface variants — match the port count and video interface to your workstation inventory before standardizing on a model.
Frequently Asked Questions
Q: What video connections does the SC940DVI-400 support?
A: The SC940DVI-400 supports DVI-D to DVI-D and DVI-D to HDMI video connections, with UHD 4K resolution at 30Hz maximum across all four ports.
Q: Can the SC940DVI-400 output 4K at 60Hz?
A: No. The SC940DVI-400 is rated for UHD 4K at 30Hz. The DVI-D interface has inherent bandwidth limits that cap 4K output at 30Hz. If 4K @60Hz is a requirement, a DisplayPort or HDMI 2.0 KVM solution is needed instead.
Q: How many computers can the SC940DVI-400 switch between?
A: The SC940DVI-400 provides 4 input ports, allowing a single operator to switch between four separate computers from one set of keyboard, video, and mouse peripherals.
Q: Is the SC940DVI-400 suitable for classified multi-domain environments?
A: The SC940DVI-400 is part of Vertiv's Cybex SC900 secure desktop KVM series, designed for multi-domain secure workstation environments with hardware-based port isolation. Buyers in regulated environments should verify current NIAP PCL listing status directly with Vertiv prior to procurement.
Q: What is the physical size of the SC940DVI-400?
A: The SC940DVI-400 has a profile height of 1.7 inches, making it a low-profile desktop unit suitable for space-constrained operator workstations.
Q: Does the SC940DVI-400 (often searched as SC940DVI 400) work with HDMI monitors?
A: Yes. The SC940DVI-400 supports DVI-D to HDMI video output, so it can drive HDMI displays directly from DVI-D computer sources without a separate external adapter at each port.
The SC940DVI-400 lands in a specific niche: four-port secure desktop switching with UHD 4K @30Hz over DVI-D — a combination that covers the majority of legacy-to-current workstation video environments without forcing a full display refresh. In my experience deploying Cybex SC900-series units, the DVI-D to HDMI flexibility on this model is underappreciated; it lets you standardize on one KVM model across a mixed monitor fleet rather than managing two SKUs by display type.
Technical Highlights:
- 4K @30Hz DVI-D Video: Full UHD resolution preserved across all four ports — analysts on GIS, imagery exploitation, or surveillance review workstations don't lose pixel density when switching between systems.
- Dual Video Path (DVI-D / HDMI): Eliminates the passive-adapter sprawl that plagues mixed-monitor deployments; the SC940DVI-400 handles the conversion natively at the switch level.
- 1.7-Inch Profile: Low enough to slot under a monitor arm base or sit flat on a regulated desk layout without consuming the vertical clearance typically reserved for paperwork or secondary displays.
Deployment Considerations:
- DVI-D bandwidth caps 4K at 30Hz — if operators require 60Hz refresh at 4K (common in video-intensive analysis workflows), this model won't meet that need and a DisplayPort-based Cybex variant should be evaluated instead.
- Confirm NIAP PCL listing currency before procurement for any formally regulated program office deployment — product certification status and product availability are independent timelines with Vertiv, and listings do expire or get superseded.
This unit is the right call for a four-domain secure workstation buildout where the installed display base is DVI or HDMI and 4K @30Hz satisfies the video fidelity requirement — government analyst desks, defense contractor multi-classification workstations, and financial compliance operations running parallel audit environments are the named scenarios where the SC940DVI-400 earns its place.
