I couldn't achieve 3600 but I think that it's pretty well tightened at 3533… not too much loss!
3 passes TM5 Anta777, another 3 passes + Furmark, 8 hours OCCT CPU/RAM, a ninth hour + Furmark and 12 hours Memtest86+ all done without error.
Thanks to everyone for the suggestions on my previous post, that helped me a lot.