PAM3 Encoding Technology: The Key to Achieving 80Gbps

Why Choose PAM3 Over NRZ or PAM4?

To achieve USB4 Gen4's 80Gbps transfer rate while using the same PCB cable specifications as Gen3, more advanced signal encoding technology must be adopted. From a technical perspective, two key factors are considered:

Total Loss Analysis

Signals travel from the host's transmitter (TX) through connectors and cables to the device's receiver (RX), experiencing signal loss throughout the entire path. Under the same cable and PCB maximum allowable loss conditions as Gen3:

• NRZ Encoding Scheme: Using traditional Non-Return-to-Zero encoding at 40Gbps transmission results in a Nyquist frequency of 20GHz, where transmission loss exceeds 40dB. This excessive loss surpasses the compensation capability of receiver ICs, preventing correct signal decoding and reception. Therefore, NRZ cannot meet Gen4 technical requirements.

• PAM4 Encoding Scheme: Using Pulse Amplitude Modulation 4-level reduces the Nyquist frequency to 10GHz, with total transmission loss approximately 23dB, which ICs can theoretically compensate for.

• PAM3 Encoding Scheme: Using three-level Pulse Amplitude Modulation, the Nyquist frequency is 12.8GHz, with total transmission loss approximately 28dB, also within IC compensation range.

After thorough evaluation by the USB-IF technical committee, PAM3 was ultimately selected as the official encoding standard for USB4 Gen4. PAM3 achieves optimal balance between spectral efficiency, power consumption control, and signal integrity, ensuring stable 80Gbps transmission on existing cable infrastructure.

USB4 Gen4 Core Specifications and Technical Features

Transfer Rate and Protocol Support

USB4 Gen4 cables support bidirectional data transfer up to 80Gbps (40Gbps × 2), equivalent to approximately 10GB of data per second. This transfer speed enables 4K movie transfers in seconds or real-time transmission of uncompressed 8K video streams.

Protocol compatibility includes comprehensive support for:

• PCIe 4.0: Provides high-speed connectivity for external GPUs, SSD drives, and expansion cards

• DisplayPort 2.1: Supports 16K@60Hz or 8K@120Hz ultra-high-resolution video output

• Thunderbolt 3/4: Backward compatible with the Thunderbolt ecosystem

• USB4 Gen3 and USB 3.2: Ensures complete compatibility with existing devices

Charging Power and USB PD 3.1 EPR

USB4 Gen4 cables feature USB Power Delivery 3.1 Extended Power Range (EPR) technology, dramatically increasing charging power from the traditional 100W to 240W (48V/5A). This breakthrough enables high-power devices such as:

• High-end gaming laptops and mobile workstations

• Professional graphics workstations

• Server-grade computing equipment

• Multi-monitor docking stations

All can perform high-speed data transfer and rapid charging simultaneously through a single USB-C port, achieving a true "one-cable" solution.

Revolutionary Video Output Capability

USB4 Gen4 cables supporting DisplayPort 2.1 protocol can output:

• 16K resolution (15360 × 8640) @ 60Hz refresh rate

• 8K resolution (7680 × 4320) @ 120Hz refresh rate

• Dual 4K displays simultaneously, each maintaining 120Hz high refresh rate

This video output capability meets the demands of professional video editing, 3D rendering, medical imaging processing, and high-end gaming scenarios.

USB4 Gen4 vs Gen3: Generational Technology Comparison

The comparison table clearly shows that USB4 Gen4 not only doubles in speed but also demonstrates significant improvements in power delivery, video output, and protocol support, representing a major evolution in USB technology.

Real-World Applications and Industry Solutions

Professional Content Creation and Video Production

For video editors, 3D animators, and photographers, USB4 Gen4 cables enable:

• Rapid backup of multi-TB raw footage files

• Real-time preview of 8K or 16K resolution video timelines

• Connection to high-speed NVMe SSD arrays for real-time video editing

• Support for multiple high-resolution monitors with synchronized display

A 100GB 4K raw footage file can be transferred via USB4 Gen4 in approximately 10 seconds, compared to 20 seconds with Gen3—doubling efficiency.

Gaming and Esports Industry

Gamers and game developers benefit from USB4 Gen4 with:

• Ultra-low latency external GPU connections: Full PCIe 4.0 bandwidth support

• 16K or multiple 4K monitor configurations: Creating immersive gaming experiences

• 240W fast charging support: Keeping high-performance gaming laptops fully powered

• High-speed external storage: Rapid loading of large game files

AI Computing and Data Science

In artificial intelligence and machine learning fields, USB4 Gen4 provides:

• High-speed dataset loading and model training

• Connection to external GPU acceleration units

• Rapid transfer and backup of large training datasets

• High-speed data exchange between multi-node workstations

Enterprise Data Centers and Servers

Data center administrators can utilize USB4 Gen4 for:

• Rapid deployment and maintenance of server equipment

• High-speed backup and disaster recovery

• Connection to high-performance storage arrays

• Support for 240W-powered edge computing devices

King Lai Electronics USB4 Gen4 Cable Technical Advantages

Premium Materials and Craftsmanship

King Lai Electronics uses industry-leading materials to manufacture USB4 Gen4 cables:

• OFHC (Oxygen-Free High Conductivity) Copper: Ensures signal transmission quality and low resistance loss

• Zinc Alloy Metal Housing: Provides excellent EMI electromagnetic interference protection

• Nylon Braided Sleeve: Enhances cable pull resistance and durability

• Cypress 2103 E-Marker Chip: Intelligently identifies devices and negotiates optimal transfer parameters

USB-IF Official Certification

King Lai Electronics is one of the few professional manufacturers in Taiwan certified by USB-IF and capable of mass-producing USB4 80Gbps 240W Type-C cables. Every cable undergoes:

• Electrical characteristics testing

• Signal integrity verification

• High and low temperature environment testing

• Insertion/removal durability testing (over 10,000 cycles)

• EMI/EMC electromagnetic compatibility testing

OEM/ODM Customization Services

King Lai Electronics provides comprehensive OEM/ODM manufacturing services, assisting clients with:

• Customized cable length and specifications

• Development of exclusive brand packaging designs

• Technical consultation and integration support

• International standard certification assistance

Application fields span industrial automation, medical equipment, automotive electronics, and consumer electronics industries.

Frequently Asked Questions (FAQ)

Q1: Are USB4 Gen4 cables backward compatible with older devices?

A: Yes, USB4 Gen4 cables are fully backward compatible with USB4 Gen3, USB 3.2, USB 3.1, USB 3.0, and USB 2.0 devices. When connecting to older specification devices, the cable automatically negotiates to operate at the highest speed the device supports, ensuring optimal compatibility.

Q2: Do I need special host or device support to use USB4 Gen4 cables?

A: To achieve the full 80Gbps transfer speed, both the host (such as a computer or laptop) and the device (such as external hard drive or monitor) must support USB4 Gen4 specifications. If only one side supports it, the speed will downgrade to the highest specification both sides support. We recommend verifying device specifications before purchasing.

Q3: How does the USB4 Gen4 240W charging function work?

A: USB4 Gen4 cables support USB PD 3.1 EPR (Extended Power Range) specification. Through the E-Marker chip, they intelligently identify device power requirements and negotiate optimal charging parameters. Charging voltage can reach 48V and current up to 5A, achieving maximum 240W power output. Only devices supporting PD 3.1 EPR can utilize the full 240W power; regular devices will negotiate to their maximum supported power level.

Q4: Does cable length affect USB4 Gen4 transfer speed?

A: Yes, cable length affects signal attenuation. For 80Gbps transfer speeds, we recommend using passive cables of 1 meter or less to ensure optimal performance. For longer distances (2 meters or more), we recommend choosing versions equipped with active signal amplifiers (active cables) or using repeater extenders to maintain signal quality.

Q5: How can I confirm if my device supports USB4 Gen4?

A: You can verify through the following methods:

1. Check device specifications for "USB4 Gen4," "USB4 80Gbps," or "USB4 Version 2.0" markings

2. Look for "USB4" markings or lightning bolt symbols near the port

3. Consult the manufacturer's website technical specifications

4. Use system utility software (such as Windows Device Manager) to check USB controller specifications

Q6: What's the difference between USB4 Gen4 and Thunderbolt 4?

A: USB4 Gen4 (80Gbps) doubles the transfer speed of Thunderbolt 4 (40Gbps). USB4 Gen4 supports DisplayPort 2.1 and PCIe 4.0, while Thunderbolt 4 supports DisplayPort 1.4 and PCIe 3.0. However, USB4 Gen4 is backward compatible with Thunderbolt 3/4 devices. Selection should be based on actual application requirements and device ecosystem considerations.

Q7: Will USB4 Gen4 cables heat up during use?

A: During high-speed data transfer or high-power charging (such as 240W), the connector portion of the cable will generate moderate temperature rise, which is normal. King Lai Electronics' USB4 Gen4 cables use high-quality materials and heat dissipation design to ensure temperature remains within safe ranges. If you notice abnormal overheating, please stop using and contact the supplier for inspection.

Q8: What quality assurance does King Lai Electronics provide for USB4 Gen4 cables?

A: King Lai Electronics' USB4 Gen4 cables are USB-IF officially certified and undergo rigorous quality control processes. Every cable passes multiple test validations, including electrical characteristics, insertion/removal durability (over 10,000 cycles), and high/low temperature environment testing. We provide complete after-sales service and technical support. Please contact customer service for details.

Q9: What should I pay attention to when purchasing USB4 Gen4 cables?

A: When purchasing, please note:

• Verify if the product has USB-IF official certification

• Check if it includes an E-Marker chip (essential component)

• Understand how cable length affects transmission performance

• Confirm if supported charging power meets your requirements

• Choose reputable manufacturers to ensure quality and after-sales service

Q10: How can I contact King Lai Electronics for product consultation or ordering?

A: You can reach us through:

• Phone: +886-2-2437-1118

• Email: andy@king-lai.com.tw

• Our professional team will provide comprehensive technical consultation, product specification explanations, and customization service support.

Why Choose King Lai Electronics USB4 Gen4 Cables?

Proven Manufacturing Excellence

With decades of experience in cable manufacturing and USB-IF certification, King Lai Electronics has established itself as a trusted supplier in the industry. Our state-of-the-art automated production facilities ensure consistent quality and reliability across every cable produced.

Comprehensive Testing and Quality Assurance

Every USB4 Gen4 cable undergoes rigorous multi-stage testing:

• Signal Integrity Testing: Verifying 80Gbps transfer stability across the full length

• Power Delivery Testing: Confirming safe and efficient 240W charging capability

• Durability Testing: Exceeding 10,000 insertion/removal cycles

• Environmental Testing: Operation verified from -20°C to 85°C

• EMC Compliance: Meeting international electromagnetic compatibility standards

Industry-Leading Technical Support

Our engineering team provides expert technical support throughout your project lifecycle:

• Pre-sales technical consultation and specification guidance

• Custom cable design for specific applications

• Integration support for complex systems

• Post-sales troubleshooting and warranty service

Global Supply Chain Reliability

King Lai Electronics maintains robust supply chain management, ensuring:

• Consistent product availability for mass production orders

• Flexible MOQ (Minimum Order Quantity) for different project scales

• Rapid prototyping for custom designs

• On-time delivery with reliable logistics partners

The Future of USB4 Technology

USB4 Gen4 represents just the beginning of the next generation of connectivity. As the industry continues to evolve, we can expect:

• Integration with emerging technologies like Wi-Fi 7 and 5G

• Enhanced power delivery capabilities beyond 240W

• Improved cable materials for longer lengths at full speed

• Wider adoption across consumer, professional, and industrial applications

King Lai Electronics remains committed to staying at the forefront of USB technology development, continuously investing in R&D to bring cutting-edge solutions to our customers.

USB4 Gen4 (Version 2.0) represents a quantum leap in USB technology, with 80Gbps transfer rates, 240W charging capability, and 16K video output support, delivering unprecedented performance experiences for professionals, content creators, and technology enthusiasts.

King Lai Electronics, as an industry-leading USB4 cable manufacturer, leverages deep technical expertise and USB-IF certification to provide customers with high-quality, high-reliability USB4 Gen4 80Gbps 240W cable products. Whether for personal use or enterprise procurement, we deliver the most professional solutions and technical support.

Ready to experience the power of 80Gbps ultra-high-speed transfer? 

Contact King Lai Electronics today and let us help you step into the new era of connectivity.

Contact Information:

• Phone: +886-2-2437-1118

• Email: andy@king-lai.com.tw

• Website: www.king-lai.com.tw

Trust King Lai Electronics for your USB4 Gen4 cable needs—where innovation meets reliability.