HP ProDesk 400 G4 Mini with M.2 NVME EXp GDC
I've literally spent all last weekend trying to add my egpu to a HP Prodesk 400 G4 Mini via the M.2 NVME slot. It comes with 2 nvme slots of which one has the ssd.
The egpu (exp GDC M.s x4) and enclosure work on on my existing Lenovo AIO but wanted to try it on this new HP but no avail.
The card gets detected fine in Windows, I proceed to install the latest nvidia drivers it then asks me to restart, when I boot back in (using the internal display port on the hp) things start getting slow i.e opening windows, typing text etc. When I look at the device in Device Manager it says the device is working, no error codes. However under the events tabs it says "...requires further installation."
If I then try to plug the external monitor to the egpu it works for a few seconds, whilst working the speakers emit a strange hissing noise then reboots windows. (The hissing noise does not happen on my lenovo as it's the same egpu).
I now know that HP has a very complicated secure BIOS but given that Windows detects the card I'm assuming its not the BIOS.
If I can't get it working I'll have to return the PC 🙁
Has anyone experienced anything similar? @nando4?
Thanks in advance,
Just to make sure it's not some software setting, consider booting a Ubuntu live USB stick and see if your eGPU outputs to an attached LCD. If the problem persists across multiple OS then have confidence it's a HW problem.
Have seen the choppy sound & slow boot as a symptom of a bad PCIe link undergoing many comms retransmissions due to a bad/faulty eGPU adapter.
While the EXP GDC may work on one system it may fail on another. Such is the tight electromagnetic signal tolerances when dealing with Gen2/Gen3 signals that slight impedance differences make a noticeable difference.
You may have some luck straightening out the interconnect cable (EXP GDC <-> M2 slot) to improve things.
Thanks for info @nando4
This makes sense as in my Lenovo setup where it works, although I'm using the M.2 NVme Exp Gdc, the Lenovo just has an M2 Sata port so it's half the speed thus maybe why at full NVme (x4 lanes) it maybe struggling due to the impedance differences you say.
I suppose I won't know this unless I buy the ADT-Link egpu will I?