The speed of a QSFP (Quad Small Form-Factor Pluggable) module can vary depending on the specific version or standard it adheres to. QSFP modules are used in high-speed data communication applications and support various data rates. As of my knowledge cutoff in January 2022, here are some common QSFP modules and their associated data rates: 

1. QSFP:

• The original QSFP module supports data rates of up to 40 Gbps. It is often used for 40 Gigabit Ethernet applications.

2. QSFP+:

• QSFP+ (Quad Small Form-Factor Pluggable Plus) is an updated version that supports higher data rates. It can operate at data rates of 40 Gbps and 100 Gbps. QSFP+ is commonly used for 40 Gigabit Ethernet and 100 Gigabit Ethernet applications.

3. QSFP28:

• QSFP28 supports data rates of up to 100 Gbps. It is widely used for 100 Gigabit Ethernet applications and is a common choice for high-speed data center networking.

4. QSFP56:

• QSFP56 (Quad Small Form-Factor Pluggable 56) supports data rates of up to 200 Gbps or 400 Gbps. It is designed for higher-speed applications and is used for 200 Gigabit Ethernet and 400 Gigabit Ethernet.

5. QSFP-DD:

• QSFP-DD (Quad Small Form-Factor Pluggable Double Density) is an extension of the QSFP28 standard. It supports higher data rates of up to 200 Gbps or 400 Gbps. QSFP-DD is designed to provide double the electrical lanes, enabling increased data throughput.

6. QSFP-DD800:

• QSFP-DD800 is a further extension, designed to support data rates of up to 800 Gbps. It is part of ongoing efforts to increase the data rates supported by optical transceivers.

It's important to note that the speed of a QSFP module is determined by its standard or version. When selecting a QSFP module for a specific application, it's crucial to ensure compatibility with the networking equipment and infrastructure, as well as adherence to the required data rate standards. Additionally, newer standards may continue to emerge to meet the evolving needs of high-speed data communication.