Is the HP Thunderbolt3 PCIeCard compatible with an HP z820 workstation?

[HughGrahamatVA]

My HP z820 workstations have x4 PCI-E Gen 3 slots for the HP Thunderbolt 3 card, but I'm not sure if the motherboard will support the card's GPIO cable. 

[DGroves]

HP released a Thunderbolt 2 card based on the reference Intel card for the zx20 line and a TBolt 3 card for the later zx40 systems  the z840 uses a 5 pin gpio cable unlike the z820's custom gpio cable that connects to 2 usb headers

every TBolt card i have seen has a 10 pin header on it which connects to the motherboards header,

read the information below for general Thunderbolt information

while it "might" be possible to install a TBolt 3 card in systems like the Zx20 series that only came with TBolt 2 cards, keep in mind that  you will not get TBolt 3 speeds in systems that have a pci-e 2.0 bus (TBolt 3 needs pci-e 3.0 for the full data speeds)

the HP z820 was unique as the engineers added thunderbolt late in the motherboards design cycle, as such they were unable to use a dedicated thunderbolt header on the motherboard, so what they did was repurpose two of the usb 2.0 headers on the board for the necessary TBolt signals you need this specific cable for the card to work in the z820 i don't know if the z420/620 used the same cable as the z820

while most wenders (like dell lenovo)  settled on using a dedicated 5 pin header on the motherboard, there is no guarantee  each board maker followed the same pinout, so a dell cable may or may not work on the lenovo board and vice versa