Hi @old_geekster,
Many thanks for your suggestion.
However, I do not consider that the great noise came just from Samsung memory. I have also installed Micron 32GB 2Rx4 PC4-2400T-R in this Z640 (HP Kit Part Number: T9V41AA [Page 15 of QuickSpecs of Z640 Version 22: http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04400040]). The same problem of noise still occurred with Micron memory. Please see the attached picture.
Could you please ask HP Supporter? Were 32GB DDR4 (LRDIMM and RDIMM) tested in the Z640 Workstation? From Z840 QuickSpecs you can see that Z840 has the lower noise emissions with 32GB DDR on the Page 27-28 (http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04400043).
The noise emissions of Z640 were only carried out with 8GB and 16GB DDR4, not 32GB DDR4. Perhaps the available BIOS of Z640 have the problem with 32GB DDR4 and lead to compatibility with any 32GB DDR4, whether Samsung / Micron / Hynix.
