Openterface Mini-KVM Mouse Speed & Gaming Performance on macOS
Gaming-Focused Mouse Behavior Analysis
This article summarizes real-world mouse performance testing of Openterface Mini-KVM on macOS, with a focus on gaming-related mouse behavior, serial baud-rate limitations, and recommended configurations.
Gaming isn't the main goal of Openterface KVMs, but we pushed them to explore the limits of KVM-over-USB. On macOS, 115200 baud + Relative HID gives the best mouse latency. Built for setup and debugging, tuned to stretch performance further. pic.twitter.com/ianurD9ArL
— TechxArtisan (@TechxArtisan) December 23, 2025
1. Test Software & Environment
Software
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Host Application: Openterface for macOS v1.21 (Work in Progress)
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Target-side Measurement Tool: A custom in-house testing application developed to accurately measure high-frequency mouse input and event processing rates on the target system.
⚠️ Because v1.21 is still under active development, some behaviors and performance characteristics may improve in future releases.
Testing Conditions: Mouse Speed Throttling
No mouse speed throttling or artificial rate limiting was applied during any of the tests.
Mouse input was captured and forwarded at native device speed, subject only to:
- Mouse hardware polling rate
- Selected mouse mode (Absolute / Relative Event / Relative HID)
- Serial baud rate
- Target OS mouse input handling
2. Mouse Data Throughput Basics
Each mouse movement event transmitted through Mini-KVM consists of:
Theoretical Serial Throughput
| Baud Rate | Max Events / Second |
|---|---|
| 9600 | ~109 events/s |
| 115200 | ~1309 events/s |
⚠️ These values represent upper theoretical limits. Actual performance is influenced by:
- Host mouse polling rate
- Mouse mode (Absolute vs Relative)
- macOS input event scheduling
- Serial buffering and firmware handling
- Target OS mouse polling rate, which can significantly affect perceived responsiveness (e.g. low default polling rates on some Linux distributions)
3. Test Results
A. Absolute Mouse Mode (9600 & 115200 Baud)
| Mouse Type | Baud Rate | Host Rate (Hz) | Target Rate (Hz) | Notes |
|---|---|---|---|---|
| Bluetooth | 9600 | ~125 | ~75 | Serial bandwidth saturated; input queued, movement delayed |
| Wired | 9600 | ~150 | ~75 | Serial bandwidth saturated; input queued, movement delayed |
| Gaming | 9600 | ~1000 | ~75 | High-frequency input heavily queued; responsiveness severely reduced |
| Bluetooth | 115200 | ~125 | ~125 | Stable 1:1 host-to-target mapping |
| Wired | 115200 | ~175 | ~175 | Improved throughput; latency appears under fast motion |
| Gaming | 115200 | ~1000 | ~350 | Serial throughput limit reached; excess input queued |
Conclusion (Absolute Mode):
Absolute mouse mode scales with baud rate but remains constrained by serial throughput and input buffering. At 9600 baud, all mouse types are bottlenecked and movement is delayed. At 115200 baud, standard mice achieve stable behavior, but high-polling gaming mice still exceed available bandwidth, introducing latency.
Absolute mode is suitable for desktop control, not for latency-sensitive gaming.
B. Relative Mouse Event Mode
Relative Mouse Event Mode captures mouse movement events directly from the operating system window, computes the movement delta between consecutive cursor positions, and forwards only the relative motion data to the target system.
This mode:
- Does not require additional system permissions
- Is independent of absolute screen coordinates
- Benefits from a larger capture window, allowing finer-grained movement deltas
- Avoids absolute-position buffering, resulting in lower latency and better responsiveness
Relative Mouse Event Mode Performance
| Mouse Type | Baud Rate | Host Rate (Hz) | Target Rate (Hz) | Notes |
|---|---|---|---|---|
| Bluetooth | 9600 | ~100 | ~90 | Near serial limit; stable for casual use |
| Wired | 9600 | ~125 | ~90 | Serial bandwidth saturated; minor latency |
| Gaming | 9600 | ~1000 | ~100 | High polling exceeds bandwidth; input compressed |
| Bluetooth | 115200 | ~125 | ~125 | 1:1 host-to-target mapping |
| Wired | 115200 | ~180 | ~150 | Improved throughput; smooth tracking |
| Gaming | 115200 | ~1000 | ~450 | Best observed performance; serial throughput bound |
🔴 9600 baud is insufficient for high-polling gaming mice 🟢 115200 baud enables responsive gaming-class input in Relative Event mode
C. Relative Mouse HID Mode
Relative Mouse HID Mode directly converts macOS HID mouse input into HID events on the target system, bypassing window-level cursor processing and absolute coordinate mapping.
This mode:
- Operates on raw HID-level mouse events
- Does not depend on application window size
- Preserves native mouse polling characteristics
- Minimizes intermediate buffering and translation
- Delivers the lowest latency among all mouse modes
As a result, Relative Mouse HID Mode provides behavior closest to a direct USB mouse connection, especially at higher baud rates.
Relative Mouse HID Mode Performance
| Mouse Type | Baud Rate | Host Rate (Hz) | Target Rate (Hz) | Notes |
|---|---|---|---|---|
| Bluetooth | 9600 | ~100 | ~90 | Near serial limit; acceptable for basic use |
| Wired | 9600 | ~250 | ~180 | Serial bandwidth partially saturated |
| Gaming | 9600 | >1000 | ~90 | High polling exceeds available bandwidth |
| Bluetooth | 115200 | ~160 | ~155 | Near 1:1 host-to-target mapping |
| Wired | 115200 | ~250 | ~150 | Stable and responsive |
| Gaming | 115200 | >1000 | ~500 | Best overall performance; serial throughput bound |
Key Takeaways (Relative HID Mode):
- Provides the lowest latency of all mouse modes
- At 9600 baud, high-polling mice remain bandwidth-limited
- At 115200 baud, gaming mice reach hundreds of target-side events per second
- Strongly recommended for gaming and fast camera movement
D. Direct Mouse on Windows (Reference)
| Mouse Type | Target Rate (Hz) |
|---|---|
| Bluetooth Mouse | 80–85 |
| Wired Mouse | 120–125 |
| Gaming Mouse | >1000 |
This reference shows that Mini-KVM (115200 baud, HID Relative mode) can approach native wired mouse performance, though it cannot fully eliminate inherent KVM and serial transport overhead.
4. Recommended Gaming Configuration
✅ Recommended
- Mouse Mode: Relative Mouse HID
- Baud Rate: 115200
- Mouse Type: Wired or gaming mouse
- Polling Rate: ≤1000 Hz recommended
❌ Avoid
- Absolute mouse mode for gaming
- 9600 baud with high-polling mice
- Excessively high polling rates without sufficient serial bandwidth
5. Important Expectations
Openterface Mini-KVM is primarily designed for:
✔ BIOS / UEFI interaction ✔ System setup and debugging ✔ Remote access and management
While gaming is possible, Mini-KVM is not a replacement for a direct USB gaming mouse, especially for highly competitive or latency-critical titles.
6. Final Summary
- Gaming with Openterface Mini-KVM is possible when configured correctly
- Gaming responsiveness is dominated by mouse mode, polling rate, and baud rate, not host CPU performance
- Absolute mouse mode prioritizes positional accuracy and is unsuitable for gaming
- 9600 baud creates a hard input bandwidth ceiling
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Relative Mouse HID mode at 115200 baud delivers the best balance of:
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Input frequency
- Latency
- Stability
- While Mini-KVM cannot fully match a native USB connection, it can provide a playable and responsive experience for casual and some competitive gaming scenarios
Overall verdict
✅ Technically solid ✅ Clear positioning for gamers ✅ Honest about limitations