HP Z8 G4 Workstation boot no video with many different GPU

[SmileM]

Hello, I just got new HP renew Workstation from sealed box ! HP Z8 G4 bios was P60 v02.90 Tried these GPU with no video signal error on monitor. Tried DVI, Display Port. Quadro 2000 HP part number 671136-001 Quadro 6000 HP part number 616078-001 ASUS Nvidia GTX 660 ATI Radeon HD 3450 ASUS GeForce 6200LE Asus EN7600GT SILENT The PC tries to post fans spin, no errors nothing. no video signal error on monitor. Tried DVI, Display Port. THEN I tried the RTX 1660 Super I had in my Z800. And the Z8 G4 Posted fine !!!!! Afterwards found this thread https://support.hp.com/us-en/document/c06718457 Updated BIOS to latest version P60 v02.94 After BIOS update all cards that do not work shows error 3 red 3 white ( 3.3 The embedded controller has timed out waiting for BIOS to return from graphics initialization.) HP should update the BIOS to work with these and possible other GPU cards, what nonsense is this? Proper working cards that work on Z800, Z820. Do not POST on Z8 G4 at all?????

Troubleshooting steps:

1. Tried many working GPU's 2. Update BIOS to latest version

[DGroves]

all your listed video cards EXCEPT for the nvidia 1660, are what is known as LEGACY video cards that do not work in newer systems that have a UEFI  based bios

newer systems are UEFI only while older systems were uefi/legacy capable

this appears to be due to a bug in most earlier video cards bios that  prevents them from switching from legacy mode into uefi based mode or due to the card not supporting uefi mode at all

video cards made in the last 5 years will be uefi enabled,

older ones between 5-10 years are mostly not uefi compatible although there were some exceptions