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HP Recommended
Z4 G4
Microsoft Windows 10 (64-bit)

Hi all,


I´m having a little problem with PCIe cards that I will try to install to this Z4 G4 Workstation. They are not at all recognized in Windows, no "Other Device" etc in device manager. And by adding through "Add Legacy Device" from Actions, will not get card working at all.


I´m trying to add some COM ports to this Workstation, trying to use StarTech.com cards:

"2 port native PCI Express RS 232 SErial Adapter Card with 16550 UART", PART # PEX2S553 (https://www.startech.com/Cards-Adapters/Serial-Cards-Adapters/2-Port-Native-PCI-Express-RS232-Serial...)

I have tried with drivers that came within package by CD, also tried with drivers found from startech support site. Startech promises support for Win10, but of course can not say that for sure now is that really working on newest 10 versions.


So, having Z4 G4 Workstation, Windows 10 LTSC 2019 (Tested also with another Z4 G4 with Win10 Pro 1909), latest drivers&Bios to this date. Cards are tested with older Workstation with Win7, working as supposed to be.


I´ve been trying to google for solution for this, but seems that I´m not having correct words to get some results that would help me.


And I don´t have any other PCIe card from HP or any really new worstation available here to test does this now find anything, I have only P4000 card in first slot, that one is working...


Been trying to change Bios settings that I´ve found for PCI/PCIe, no help. Bios factory defaults are not helping with this either.


Any ideas from anyone, should this combination even work on this Workstation? IF not, what kind of PCIe cards this Workstation is needing if there is something wrong in type etc. (preferrably right now would get COM-ports to this machine in less than a week)


So, any ideas?



HP Recommended

you need to be a bit more specific, did startech support say windows 10 may 2004  is not tested yet


or does this also include the previous 1909/1903 builds of windows 10?


if startech does not officially support your win 10 build on this model card why did/are you using this card in the first place?


Update: startech does list win 10 as a supported OS



your card uses a ASIX-MCS9922CV-AA chip, and you can download drivers directly from the chip makers site





the startech PEX2S952 card also does list windows 10 support





HP Recommended

Thanks, I think I will try updating those chip drivers at some point later just to test if that would solve this issue.


I got answer from StarTech, they have problems with some HP models:


"To answer your question: yes, we have seen reports of this before. Unfortunately it would seem that the chipset in our PEX2S553 has compatibility issues with HP Z4 G4 Workstations"


They replied that I could be using "PEX2S953 or PEX4S953" with Z4 G4, tried now with PEX4S953 but that seems to have problems with at least Win10 LTSC 2019 someway, driver setup will cause Windows to crash immediatelly. Windows will find correct card with driver files, but then gives me 4 not working devices.

Will have to test if two PEX2S953 cards will give me better result, but haven´t found time to do that yet, will have to test with two cards, as this machine will come to need 3 working ports soon.


But for original question, they really seem to have problems getting that PEX2S553 card work with Z4 G4 model, possibly that chipset update will help, but as stated, have not had time yet to test.

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