There’s 2 drivers: the “legacy” driver that works with firmware v20.13ish and prior, and the new “Logix Driver” that works with any firmware version but is optimized for v21+.
The new driver is not faster than the old driver. The old driver reads tag values directly out of memory. Rockwell disabled this functionality starting in 20.15? or something like that. In 21+ they introduced a new API for reading tags based on instance IDs (instead of via symbolic names).
The new API is certainly faster than reading symbolic names but it’s nowhere near as fast as direct memory access was.
Fun note: if you’re stuck on 20.xx where xx=15+ you have to use the new driver but there’s no new API so it uses symbolic access, which gives you the absolute worst performance.
I can’t remember the exact 20.xx cut-off where direct memory access stops working. I know 20.11 works with the legacy driver.