Are two CPU's required for a 6-8 GPU rig?

[dontknowmuch]

Hey friends.

My company wants to purchase a 6 GPU rig with an option for 8.

Our IT guy says that for a 4+ GPU rig, it is a must to have two CPUs, and maybe more for an 8 GPU build.

I've never heard of that, is there any truth to that?