the 6600
Model BX80562Q6600
CPU Socket Type
CPU Socket Type LGA 775
Tech Spec
Core Kentsfield
Multi-Core Quad-Core
Name Core 2 Quad Q6600
Operating Frequency 2.4GHz
FSB 1066MHz
L1 Cache 128KB+128KB
L2 Cache 2 x 4MB
Manufacturing Tech 65 nm
64 bit Support Yes
Hyper-Threading Support No
Virtualization Technology Support Yes
Multimedia Instruction MMX, SSE, SSE2, SSE3,SSSE3, EM64T
Voltage 0.85V ? 1.5V
the 8400
Model BX80570E8400
CPU Socket Type
CPU Socket Type LGA 775
Tech Spec
Core Wolfdale
Multi-Core Dual-Core
Name Core 2 Duo E8400
Operating Frequency 3.0GHz
FSB 1333MHz
L2 Cache 6MB
Manufacturing Tech 45 nm
64 bit Support Yes
Hyper-Threading Support No
Virtualization Technology Support Yes
Multimedia Instruction MMX, SSE, SSE2, SSE3, SSE4, EM64T
Voltage 0.85V ? 1.3625V
see the difference there?