How to increase maximum user cpu usage allowed on a multi core system?

[stan]

I'm running Fedora 21 with a custom compiled kernel,
3.19.0-1.20150211.fc21.x86_64.

I have a multi core system with 6 cores.  All are recognized by the
kernel.  

But, when I run a compile job with -j6, in order to allow all six cores
to be used, it limits the total amount of usage to 100% of a *single*
core.  So, it might use all six cores, but the sum of the percentages
on those six cores is always around 100% of one core.  This is from
htop output.

On large compilations, like the kernel or firefox, even using 4 cores
could drastically reduce compile time.

I've looked at /etc/security/limits.conf, but it doesn't seem to have a
setting for this.  I've also looked at the /proc system to see if there
is a kernel variable, though that seems unlikely, with no luck.  Online
searching found ways to limit the amount that a single job can get, but
not how to set this for a user.  There must be a configuration variable
somewhere that is limiting the amount of total cpu a user can use.  But
I can't find it.

Can anyone help?