Processor: shall be defined as all processors where the Oracle programs
are installed and/or running. Programs licensed on a Processor basis may
be accessed by your internal users
(including agents and contractors) and by your third party users. For
the purposes of counting the number of processors which require
licensing, a multicore chip with "n" cores shall be
determined by multiplying "n" cores by a factor of .75. All fractions of
a number are to be rounded up to the next whole number. For example, a
multicore chip with 11 cores would require a 9
processor license (11 multiplied by a factor of .75 equals 8.25 which is
then rounded up to the next whole number which is 9). Notwithstanding
the above, when licensing Oracle Standard
Edition One or Standard Edition programs on servers with a maximum of 1
processor with 1 or 2 cores, only 1 processor shall be counted.

Таким образом, берём количество ядер, умножаем на 0.75, и получаем искомое.
8 * 0.75 = 6 процессоров. :)