i7 = 4 cores on one die
C2Q = 4 cores on 2 die
C2D = 2 cores on 1 die
Pentium D = 2 cores on 2 die
C2Q = usually cheaper than i7si7 Quad = 4 cores on 1 die
Core2Quad = 4 cores on 2 die
Core2Duo/Pentium core Duo = 2 cores on 1 die
Pentium D = 2 cores on 2 die
Pentium/Celeron = 1 core on 1 die
Core2Quad = usually cheaper than i7s