The main difference between SFP (Small Form-Factor Pluggable) and SFP+ (Enhanced Small Form-Factor Pluggable) form-factors lies in their data transfer rates. Both SFP and SFP+ are types of optical transceiver modules used in networking equipment, such as switches and routers, to transmit and receive data over fiber-optic or copper cables.

1. Data Transfer Rate:

• SFP: Supports data rates up to 4 Gbps (Gigabits per second).

• SFP+: Supports higher data rates, typically 10 Gbps, and beyond. It is an enhanced version designed to handle 10 Gbps and higher-speed networks.

2. Applications:

• SFP: Commonly used for 1 Gbps and 2 Gbps applications, although some SFP modules can support higher data rates.

• SFP+: Primarily used for 10 Gbps applications, but it can also support higher data rates, such as 25 Gbps and 40 Gbps.

3. Compatibility:

• SFP: SFP modules are generally not compatible with SFP+ ports.

• SFP+: SFP+ ports are backward compatible with SFP modules, meaning you can use SFP modules in SFP+ ports, but the data rate will be limited to what the SFP module supports.

4. Form-Factor Size:

• Both SFP and SFP+ share the same physical size and shape, making them interchangeable in terms of form-factor.

In summary, while SFP and SFP+ modules have a similar form-factor, the key distinction is in their data transfer capabilities. SFP+ is designed to handle higher-speed networks, typically starting at 10 Gbps, making it suitable for modern high-bandwidth applications.