diff --git a/install_sys.sh b/install_sys.sh
index be3ce81..5915f50 100644
--- a/install_sys.sh
+++ b/install_sys.sh
@@ -28,6 +28,12 @@ echo "Europe/Paris" > $CHROOT/etc/timezone
 cp /etc/resolv.conf $CHROOT/etc/resolv.conf
 
 mirrorselect -i -c FR -o >> $CHROOT/etc/portage/make.conf
+NJOBS=$(grep '^processor' /proc/cpuinfo | sort -u | wc -l)
+MAKEOPTS="-j$((NJOBS+1)) -l${NJOBS}"
+echo MAKEOPTS='"'$MAKEOPTS'"' >> $CHROOT/etc/portage/make.conf
+echo MAKEOPTS='"'${NJOBS}" >> $CHROOT/etc/genkernel.conf
+EMERGE_DEFAULT_OPTS="--jobs=${NJOBS} --load-average=${NJOBS}"
+echo EMERGE_DEFAULT_OPTS=$EMERGE_DEFAULT_OPTS  >> $CHROOT/etc/portage/make.conf
 mkdir $CHROOT/etc/portage/repos.conf
 cp $CHROOT/usr/share/portage/config/repos.conf $CHROOT/etc/portage/repos.conf/gentoo.conf
 chroot $CHROOT /bin/bash -c "emerge --config sys-libs/timezone-data"