HP DL380p Gen8 and PCIe SSD? [duplicate]

This is mostly covered here: Third-party SSD solutions in ProLiant Gen8 servers

PCIe should be fine, regardless of the model. You may have to adjust BIOS setting to accommodate (cooling, etc.). The system fans may spin at a higher rate.

SSDs in a disk form-factor may or may not work. You have the additional challenge of finding HP SmartDrive carrier trays for the disks. Prior to the Gen8 servers, you could get away with this, but now you will receive firmware mismatch errors on the drives, or a notice that the disk is not genuine.

Update: I've tested the OWC Mercury Accelsior PCIe SSD in G6, G7 and Gen8 HP ProLiant servers. See the result here.

There are many people who run with non-HP disks and SSDs in HP servers and there are many that come here wondering why they've lost service/data etc. - generally it's a bad idea and we don't suggest that you do this due to HP-specific disk firmware incompatibilities.

That said PCIe storage is a different matter and I've been using FusionIO versions for years without an issue - the reason being that the controller is part of the adapter card, it's an 'all in one' solution - and they do just work great. I don't personally know the OCZ product but I would have no fear about using those at all.