Max number of extension blocks

[njz3]

Hi,
I developped a hardware E-EDID emulator based on a microcontroller and used CRU as the reference tool to build E-EDID v1.4 binary files and flash them into my emulator.
This is used to stored many resolutions and make them available right from Windows' display properties, mainly for retro-gaming CRT usage where you can have several dozens of different resolutions that have slightly different number of vlines or vsync (MAME arcade games for example).

So far everything works ok, I am just limited in how many extensions I can add to the E-EDID v1.4, 7 as of today 1.5.2 CRU. I tried AW EDID Editor v3.0.20 and I have the same limitation.
Do you know why there is such a limitation? Is it due to NVIDIA or AMD driver's?
Or is it a limitation of the E-EDID format itself?
Thanks

[ToastyX]

EDID supports up to 255 extension blocks, but AMD will only read up to 7, and NVIDIA will read up to 15, so CRU just sets the limit to 7. The limit used to be 3 in older drivers.

[njz3]

Many thanks for your reply.

Actually, it seems like even on my RTX2060 I can read only 7 CTA-861 extension blocks (EDID v1.4) through HDMI.
Do you know if that's something we can override somewhere ?

[ToastyX]

The limit is hard-coded in the driver.