SFP (Small Form-factor Pluggable) and QSFP (Quad Small Form-factor Pluggable) are both types of transceiver modules used for networking and communication equipment.

The main difference between SFP and QSFP cables is the number of channels they support. SFP transceivers have one channel, while QSFP transceivers have four channels, allowing for higher data throughput. This means that QSFP cables can support higher data transfer speeds and are typically used in applications requiring higher bandwidth, such as data centers and high-performance computing environments.

In addition to the difference in the number of channels, QSFP cables are physically larger than SFP cables, with QSFP cables having four times as many electrical contacts as SFP cables.

Overall, the main difference between SFP and QSFP cables lies in their data throughput capabilities and physical size, with QSFP cables being able to support higher data transfer speeds and larger bandwidth requirements compared to SFP cables.