A ring buffer is useful in situations where you need a buffered reader. Once allocated a ring buffer does not need to allocate additional memory or move bigger junks of data around.
These are simple benchmarks which calculate an average throughput of data per second.
A ring buffer based on sending arrays of data.
A ring buffer where the written data is probably not copied because its throughput is incredibly high.
A ring buffer implementation based on moving data after reading data it.
A ring buffer based on reallocating memory.
The ring buffer in this package.
If copying data is not needed when writing it, the channel implementation is unbeatable. If copying data on write is needed then this ring buffer implementations can probably be recommended.