Asus K8N-dl - second processor present but not...

Actually your 2nd cpu needs a memory to run. You need to add a memory to slot A3. Slot A3 and B3 are memory slots for 2nd cpu.

I fgured out the main issue; that is, I was not using a 8 pin mobo power connector... I love the motherboard, paid $165 for it on ebay; when it retails around 300 - 400. I have never since seen another like it on ebay. A real find and a great mobo. I recommend the Asus K8N-DL, dual opteron Mobo to anyone running dual opteros.

Hi, Mistyman here. All Asus mother boards that have dual channel RAM slot must have equal ram in each slot. In most cases the paired slots are matched by color for easy ID, some are identified by a printed ID on the mother board. With your board you will have to have run all of your RAM for the one CPU. If you have only one stick this must be in slot one. If you are using two sticks then utilise the dual chanel system that ASUS have and use A1 & A3.
To activate the second CPU you will need to install matching sticks of RAM in the B slots. both cpu's will need to have the value of RAM to work together properly.
CPU one = slot A for RAM
CPU two = Slot B for RAM.
Goodluck, the ASUS boards are a value product.