BRAVO and a very very big thank you Big_11 !!!
It worked wonderfully for an HP Z420 Workstation baremetal.
With :
XEON E5 1620 3,6Ghz 4 cores
+ Intel X550-T2 10Gbps NIC
+ SATA 3 88SE9239 PCIe v2 x4
The info center show : Intel Core i3-4130 3,6Ghz 2 cores, but anyway better that than nothing.
Small question :
is there any tutorial to learn how to transform Jun synoboot to MBR ?