Tvheadend

Hi !
my ubuntu 14.04 machine is an Core i3 with a 512 GB SSD... it runs serveral services including tvheadend (stable package)
usually when idling machine has a load around 0.1 !
I setup first tvheaden with an octopus net as source using all 4 devices and a while after startup and downloading / scanning it reaches idle load also about 0.1
So now i bought a Cine S2 (V6.x) with 4 tuners and made a Unicable setup (i have only one cable there)
when i enabled the 1st dvb device on Cine S2 idle load will be around 1.1
with 2nd device it reaches after 15 minutes 2.0
with 3rd 2.6 and finally having complet card enabled load avg is about 3.1 !!!
And again the machine does nothing during that time (no transcoding/recording whatever top shows following CPU Values
%Cpu0 : 4,8 be, 1,6 sy, 0,0 ni, 93,7 un, 0,0 wa, 0,0 hi, 0,0 si, 0,0 st
%Cpu1 : 0,0 be, 1,5 sy, 0,0 ni, 98,5 un, 0,0 wa, 0,0 hi, 0,0 si, 0,0 st
%Cpu2 : 0,0 be, 0,0 sy, 0,0 ni,100,0 un, 0,0 wa, 0,0 hi, 0,d go b0 si, 0,0 st
%Cpu3 : 0,0 be, 0,0 sy, 0,0 ni,100,0 un, 0,0 wa, 0,0 hi, 0,0 si, 0,0 st

I tried with all passible constellation setting up device (idle scan / power save and and and) result is always the same

If i disable them all and go back to my satip server source setup i'll reach again after a while 0.1 :)
But not enough... i setup vdr on same machine also unicable setup using cine S2 and all 4 devices => again an idel load around 0.1 :)
recording on all 4 devices with 4 HD streams result on a load avg about 2.5 ...
So whats wrong with tvh ?

Ciao Ger