Drivers for the Z820 can be found here, just select the OS of choice....
If not already done, i'd apply the chipset drivers and the Intel Rapid Storage Drives and see if that resolves the problem.
But somewhow i doubt it would Image may be NSFW.
Clik here to view.
Oddly HP does not list Win10 drivers for SAS RAID cards, only Win7 drivers !
This could mean that HP hasn't as yet pulled it's finger out and released the Win10 drivers for these RAID cards, or the drivers are natively included in Win10 (but why then would you then get code10? yellow bung).
It wouldn't surprise me if HP has complied the base workstation for Win10 but hasn't bothered doing the same for the RAID cards that could be ordered with this machine!
Maybe you need to call HP.
