ASUS Technical Data

The table below shows the specifications of the Intel Duo Core processors

 

E8500 E6850
# of Cores 2
# of Threads 2
Processor Base Frequency 3.16 GHz
Cache 6 MB L2 Cache
Bus Speed 1333 MHz
FSB Parity No
TDP 65 W
VID Voltage Range 0.8500V-1.3625V
# of Cores 2
# of Threads 2
Processor Base Frequency 3.00 GHz
Cache 4 MB L2 Cache
Bus Speed 1333 MHz
FSB Parity No
TDP 65 W
VID Voltage Range 0.8500V-1.5V

This link discusses the use of the 2nd PCIE_16 slot for a PCIE_1 card such as the Creative Sound Blaster Fx Audigy. 

https://forums.techguy.org/threads/solved-pcie-slot-not-working-on-asus-p5n-e-sli.1114972/