Hi,
I'm currently having a HP Z820 workstation and I have a new purchase Samsung SSD that would like to install on my Z820.
I do found a technical white paper white mention about 668261-001:
HP Z620 and Z820 Workstation Carrier Options
At the sametime I did use HP Part Surfer to check my SN# for Z820 an indeed there is a same part number delievered during the purchase.
Hope can get some technical expert help here.