The post was in the wrong HP forum branch.... here is his post, and I have edited it a bit for clarity. I'll PM him with a link to this:
His question:
Product Name: z800 OS: Microsoft Windows 7 (64-bit)
HP Z800 with dual X5670 processors. Thus, this is a version 2 Z800 with the later boot block date. I am trying to install a Kingston HyperX Predator M2 SSD boot drive, inserted in its Kingston PCIe slot "carrier" card. I can't get the computer to boot into Windows. After it goes thru the BIOS screens, it suddenly resets and starts the boot process over again, in an endless cycle. The Predator M.2 SSD drive does show up on the "boot order" screen in BIOS.
I have it installed into PCIe slot 4, and compute is enabled. The Storage Controller is 9.6.0.1014. Bios 786G5 v03.57. Boot block date is 11/10/09 (the later version motherboard). Both the vendor and Kingston says they don't support this, as the workstation is too old..... "these older motherboards....".
Here is the answer:
I have posted in this forum about how to use the Kingston Predator M.2 in its PCIe carrier card with the Z400/Z600/Z800 workstations, and even with the xw workstations, and I have it working in the Z620 too. Have the latest BIOS installed. Have the proper Storage Controller driver installed on the build.... that is the key. It is easiest to have the build all tuned up on a regular 2.5" form factor SSD with the proper storage controller driver present. For the ZX00 workstations it is specifically that 9.6.0.1014 one. Then use Acronis to capture the image of that build. I use an eSATA attached external drive for that, but you can also use a USB attached external drive. Then place the Predator (in its carrier card) in the chosen PCIe slot (a PCIe x16 slot that would be usable for a second video card would work fine). Remove all other drives. Boot into Acronis and load the image onto the Predator M.2 SSD. Boot from the Predator. Add in other HDD or SSD drives after.
He has the correct storage controller driver. He should upgrade his BIOS to 3.60.
His key mistake: the default for all the PCI/PCIe slots is to have load option ROM enabled and Compute disabled. Either he or someone before him set that slot 4 in BIOS to Compute enable. It needs to be set to disable. You get to that in BIOS via the far right column, down under the PCI slot listing.