The NEC V20 was a cheaper, pin-compatible clone of the Intel 8088 processor. While the first 8088s only ran at 4.77 MHz, the V20 offered faster speeds of 8 and 10 MHz (although most PC manufacturers included a "turbo button" that allowed you to slow it down to 4.77, usually to make games playable).
The V20 was commonly found in many "XT clones" sold in Southeast Asia, as Intel was still selling their chip at prohibitive prices. Intel did sue NEC for allegedly "reverse-engineering" their product, but I believe it was settled out of court. Despite this, the V20 was instrumental in the development of hundreds of small clone manufacturers in the Asia-Pacific region. My first PC in 1989 was a V20, since the one with a genuine Intel chip cost nearly twice as much.
Sony licensed the V20 from NEC for use as embedded controllers, and the Sony version can be found in 8, 10, and 16 Mhz versions.
Details verified from Aad Offerman's Chiplist, at http://einstein.et.tudelft.nl/~offerman/chiplist.html