Form Factor

OSFP follows the OSFP MSA (www.osfpmsa.org)which is led by Arista, while QSFP-DD follows the QSFP-DD MSA (www.qsfp-dd.com) which is led by Cisco. Besides that, OSFP is slightly bigger than QSFP-DD.

The OSFP package is slightly larger than the QSFP-DD package, but like the QSFP-DD, it still supports 36 OSFP ports per 1U front panel, enabling 14.4 Tbps per 1U.

Power Consumption and Heat Dissipation
Due to its larger size, the OSFP package has a higher thermal capacity, OSFP can handle higher power consumption, up to 15W, and provide better heat dissipation and signal stability. In contrast, the QSFP-DD module can only handle a maximum of 12W of power consumption due to size limitations, which is relatively more energy-efficient.
Compatibility
QSFP-DD is designed with backward compatibility, so it is perfectly backward compatible with QSFP, QSFP28, QSFP56 and 400G QSFP-DD interfaces, helping you achieve seamless upgrades and cost savings. On the other hand, OSFP is slightly larger and can only be used on devices equipped with OSFP ports. Therefore, infrastructure updates are usually required to adapt to its larger size and connector interface, leading to higher hardware modification costs during deployment.
Application
From the perspective of application fields, QSFP-DD is generally widely used in the Ethernet field. However, OSFP has a broader range of applications, including Ethernet networking, InfiniBand, and high-performance computing.
For example, QSFP-DD 800G DR8 modules can be used in Ethernet, data centers, and 800G to 2x 400G applications, while OSFP 800G DR8 modules are suitable for InfiniBand NDR end-to-end systems in addition to these scenarios.