Unbuffered Memory is a memory that has no register between your DRAM and your system's memory controller. It leads to a direct access to your memory controller (normally integrated to your motherboard) and would now be more efficient than your registered ones.

Is buffered or unbuffered RAM better?

Buffered RAM provides more stability to the system than unbuffered RAM.

Is unbuffered memory better?

Why is unbuffered memory a better choice than buffered memory for gaming or general use computers? ... The additional control circuitry on the unbuffered RAM module speeds up memory reads. The computer can read data directly from the unbuffered memory banks, making unbuffered memory faster than buffered memory.