What you need to know about Optcore 400G QSFP-DD DAC Cables

Introduction

400G optical transport technologies are currently in high demand due to the exponential development of network and data traffic. To meet these demands, Optcore has introduced the 400G QSFP-DD DAC and 400G breakout DAC cable, which is primarily suited for ultra-short-haul applications in data center interconnect (DCI) and offers robust performance, reliability, and flexibility. This post will introduce those 400G DAC cables.

Features and Specification

The 400G DAC cable can be divided into 400G QSFP-DD to QSFP-DD DAC and 400G QSFP-DD breakout DAC cable. The below table shows the detailed specifications of the 400G DAC cable.

Category	Part #	Data Rate	Length	Modulation	Power Consumption
400G QSFP-DD DAC	QDD-400G-DAC-P50CM	400G	0.5m	PAM4	0.1W
400G QSFP-DD DAC	QDD-400G-DAC-P1M	400G	1m	PAM4	0.1W
400G QSFP-DD DAC	QDD-400G-DAC-P2M	400G	2m	PAM4	0.1W
400G QSFP-DD DAC	QDD-400G-DAC-P3M	400G	3m	PAM4	0.1W
400G QSFP-DD to 2x QSFP56 Breakout DAC	QDD-2Q56-DAC-P50CM	400G/200G	0.5m	PAM4	0.5W
400G QSFP-DD to 2x QSFP56 Breakout DAC	QDD-2Q56-DAC-P1M	400G/200G	1m	PAM4	0.5W
400G QSFP-DD to 2x QSFP56 Breakout DAC	QDD-2Q56-DAC-P2M	400G/200G	2m	PAM4	0.5W
400G QSFP-DD to 2x QSFP56 Breakout DAC	QDD-2Q56-DAC-P2.5M	400G/200G	2.5m	PAM4	0.5W

Highlights of Optcore 400G QSFP-DD DAC Cable

• PAM4 modulation: Unlike the 100G QSFP28 DAC cable, the 400G DAC cable features PAM4 modulation, reaching data rates of up to 50 Gbps per lane. And support 8x 50Gbps data rate or 4x 100Gbps.
• Cost-effective: Compared with the 400G transceiver and 400G AOC cable, the 400G DAC cable is more cost-effective. Its lower pricing will save the total cost of data center cabling and investment.
• High Speed: 400G DAC cables are specially designed for 400G applications, providing a higher data rate and more reliable connection than 100G QSFP28 DAC cables.
• Compatibility: The Optcore 400G DAC cable is compatible with existing equipment that supports the 400G Ethernet standard, such as the mainstream switches, routers, and other platforms.
• Excellent heat dissipation: the DAC cable uses a copper cable to ensure optimal signal integrity. So the DAC cable has a better heat dissipation performance than the 400G AOC and 400G transceiver.
• Low power consumption: Compared with the other 400G AOC and 400G transceivers, this passive DAC cable provides a much lower power consumption. It will help reduce the heat generation in the data center and save energy costs.

FAQs about Optcore 400G QSFP-DD DAC Cable

Q: Can Optcore custom 400G QSFP-DD DAC based on customer needs?

Optcore 400G DAC length can be 100% customized based on customer needs. But please expect a longer lead time for this customized product.

Q: What are the applications of 400G DAC?

The 400G DAC is mainly used for short-haul applications like the link between switches/routers within racks and adjacent racks.

Q: Can I plug 400G QSFP-DD DAC into an OSFP port?

A: No, because they are different form factors. You should plug 400G QSFP-DD DAC into the 400G QSFP-DD port and 400G OSFP DAC into the OSFP port.

Q: Can I plug 400G QSFP-DD DAC into a QSFP28 port?

A: No, 400G QSFP-DD DAC is incompatible with the QSFP28 port.

Q: What’s the difference between 400G AOC and 400G DAC cable?

A: The main difference is the media type. DAC uses a copper cable, while AOC uses fiber cable. 400G DAC is much cheaper than 400G AOC in the market.

Q: What are the QSFP-DD means?

The QSFP-DD means Quad Small Form-Factor Pluggable Double Density, and it is an enhanced version of the existing QSFP form factor.

Q: Is it possible to have an OSFP on one end of a 400G link and a QSFP-DD on the other?

Yes. The OSFP and QSFP-DD describe the module’s physical form factor. OSFP and QSFP-DD modules can communicate with one other if the Ethernet media types are the same (for example, if the link is 400G-DR4 or 400G-FR4, etc.).

Q: What is the difference between a 400G DAC and a 400G breakout DAC?

A: They have a different connector on another end. 400G DAC has a QSFP-DD connector on both ends, while 400G breakout DAC has a QSFP-DD connector and hybrid connector (like QSFP28, QSFP56, or SFP56) on another end.

In addition, the data speed on the other end is also different. Both ends of the 400G DAC support 400Gbps speed, while the 400G breakout DAC splitter 400Gbps to 8x50Gbps, 4x100Gbps, or 2x200Gbps on another end.

Q: Can I use 400G AOC instead of 400G DAC?

A: Yes, if you do not care about the pricing. 400G AOC is much more expensive than 400G DAC. We suggest you use DAC for short links <3m and AOC for the long links.

Q: What’s the benefit of using a 400G DAC rather than a 400G AOC?

A: 400G DAC is much cheaper and easier to deploy than 400G AOC. 400G DAC is also suitable for very short links, while 400G AOC is more commonly used for long-haul applications.

Conclusion

400G QSFP-DD DAC cables from Optcore are well suited for ultra-short-haul Data Center Interconnect (DCI) applications. They offer robust performance, reliability, and flexibility. If you’re looking for a 400G cable solution that can meet your high-speed data needs, consider Optcore’s 400G QSFP-DD DAC cables.

If you have any other questions, please feel free to contact us. Optcore is always here and ready to help. Have a good day!