Does Slackware/Unraid make use of multiple processors if available?  My server's M/B supports a second processor & RAM...thinking that might be a less expensive performance upgrade- particularly with version 6 somewhere on the horizon.  But for now- working with 5.05

8 cores are supported in v5,  this was upped to 16 in 6b6.

Is it okay if those 8 cores aren't within ONE processor?  (Forgive my ignorance.  I've never had more than one physical processor on a M/B.)

Yes, it works. I've had a number of motherboards with multiple processors.

Does Slackware/Unraid make use of multiple processors if available?  My server's M/B supports a second processor & RAM...thinking that might be a less expensive performance upgrade- particularly with version 6 somewhere on the horizon.  But for now- working with 5.05

 

That will be upped to 256 processors in unRaid6-beta7.

 

BTW has nothing to do with the distro (eg, slackware) - this is purely a linux kernel configuration knob.