The real challenge is the architecture — not the bandwidth.
As 8K displays and high-performance workstations become increasingly common in professional environments, users often ask a seemingly simple question:
If a 4-port 8K KVM already exists, why is it so difficult to scale to 8 or even 16 ports?
At first glance, this seems to be a bandwidth issue. After all, 8K60 is already pushing the limits of HDMI 2.1.
In the actual development of KVM systems, However, bandwidth is not the primary bottleneck..
The real challenge lies in the architecture.
This article explains why scaling of 4-port to 8-port and 16-port 8K KVM switches fundamentally an architectural problem — and why only a few products can reliably implement this.
1. An important clarification: KVMs do NOT process all video streams simultaneously.
A common misconception is that an 8-port or 16-port KVM must process all incoming 8K video streams internally simultaneously..
This is how it works professional KVM switches not.
In a typical KVM design, the following applies:
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At any given time only a single input video signal is actively passed to the output
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Unselected inputs retain link presence (EDID, HDCP status), but are not fully processed or forwarded
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The system behaves like a High-speed signal router, not like a parallel video processor
This difference is crucial.
This means that the transition from 4 ports to 8 or 16 ports not This requires multiplying the raw video bandwidth within the system.
2. The bandwidth issue for individual 8K ports has already been resolved.
An 8K60 HDMI 2.1 signal requires approximately:
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~45–48 Gbit/s FRL bandwidth
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Precise clock recovery, equalization, and jitter control
Modern HDMI 2.1 transceivers already support this.
Out of pure bandwidth perspective Processing a single 8K60 signal is no longer a challenge.
Therefore, reliable 4-port 8K KVMs already exist today.
3. The real limitation: The 4×1 nature of HDMI switching chips
Most HDMI 2.1 switching solutions — including Analog Devices ADV7674 — are fundamentally based on a 4-entrance/1-exit architecture.
What the ADV7674 actually is
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4 HDMI 2.1 inputs
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1 HDMI 2.1 output
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Supports up to 48 Gbit/s FRL
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Integrated EDID management and HDCP 2.3
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Fast input switching (InstaPort™)
In other words: The ADV7674 is not a Matrix chip..
He is a high-performance 4×1 switching module.
This design decision was a conscious choice:
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It minimizes latency.
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It avoids unnecessary internal bandwidth.
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It ensures signal integrity at extreme data rates.
4.Why scaling from 4 → 8 → 16 ports is an architectural leap
Once you understand the 4×1 nature of the switching chips, the real difficulty becomes clear.
4-Port 8K KVM
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An ADV7674
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An HDMI output path
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Relatively simple control logic
8-Port 8K KVM
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Several ADV7674 building blocks
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Hierarchical or cascaded switching topology
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Coordinated EDID and HDCP status management
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Deterministic switching behavior across multiple chips
16-Port 8K KVM
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Further scaling of the same concept
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Significantly stricter timing control
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Higher firmware complexity
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Greater validation effort
At this point, the challenge no longer lies in the electrical bandwidth —
but in the System-level orchestration.
5. The actual engineering challenges of large 8K KVMs
1) Deterministic, interference-free switching
Users expect:
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No black screens
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No retraining delays
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No visible synchronization losses
Achieving this across multiple switching chips requires:
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Precise control sequences
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Stable Clock Domains
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Predictable HDCP behavior
2) EDID and HDCP consistency across all inputs
Each connected host must:
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Detect a stable EDID
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Maintain HDCP authentication even in the unselected state
Any inconsistency leads to:
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Re-detection of display
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Resetting the resolution at the operating system level
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Application instability
3) Synchronization of USB and peripheral devices
A KVM is never just for video.
An 8-port or 16-port KVM must also manage:
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USB HID devices
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USB 3.x peripherals
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Audio paths
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Hot-plug events
Synchronizing USB switching with video selection is common more complex than the actual video routing.
4) Thermal and reliability limits
Even without parallel video processing:
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Multiple HDMI 2.1 transceivers generate heat
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High-speed routing increases EMI sensitivity.
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Long-term stability is becoming a key design requirement.
That's why large 8K KVMs are needed careful component placement, precise power supply design, and sophisticated firmware control — not just faster chips.
6.Why true 8-port and 16-port 8K KVMs are rare
To sum it all up:
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Bandwidth is no longer the limiting factor.
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The hardware already supports single-port 8K60.
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The real hurdle is the scalable switching architecture
Developing a reliable 8-port or 16-port 8K KVM requires:
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Modular switching blocks (such as 4×1 transceivers)
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Sophisticated control logic at the system level
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Extensive validation with real devices
That's why such products are rare — and many manufacturers stop at 4 ports.
7. Practical Implementations of TESmart
TESmart addresses these architectural challenges with carefully developed multi-port designs:
HKS801-M24 — 8-port 8K60 HDMI 2.1 KVM
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Based on a modular high-speed switching architecture
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Stable 8K60 HDMI 2.1 output
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Intelligent EDID and HDCP management
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Designed for professional multi-host workflows
👉 https://www.tesmart.de/products/hks801-m24
HKS1601-M24 — 16-port 8K60 HDMI 2.1 KVM
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The same architecture scales to 16 hosts.
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Central control with deterministic switching behavior
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Suitable for laboratories, studios and corporate environments
👉 https://www.tesmart.de/products/hks1601-m24
These products demonstrate that scaling 8K KVMs is possible. It's not about providing more bandwidth, but rather because of this to build the right architecture.
Key takeaway
The difficulty of building 8-port and 16-port 8K KVM switches is often misunderstood.
The real challenge is not the raw bandwidth, rather:
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Modular switching topologies
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Coordination at the system level
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A reliable and seamless user experience
Once this architectural problem is solved, true large-scale 8K KVM systems will be possible — and practically usable.
