Which USB version is NOT known for high-speed data transfer?

USB 2.0 is indeed the version that is not known for high-speed data transfer compared to the others listed. When USB 2.0 was introduced, it could support a maximum data transfer rate of 480 Mbps, which was significantly faster than its predecessor but far slower than the rates offered by later versions.

In contrast, USB 3.0 introduced a considerable upgrade with a maximum data transfer rate of 5 Gbps, while USB 3.1 Gen 2 further enhanced this with speeds up to 10 Gbps. USB 4.0 has advanced capabilities, allowing for even higher speeds and better efficiency through support for multiple data protocols.

Therefore, while USB 2.0 represented a milestone in connectivity, it does not match the high-speed data transfer capabilities of USB 3.0, 3.1 Gen 2, or USB 4.0.