A40 Displaylink Output

I am currently working on a HPC system that uses an A40 array of GPUs… i have run the display mode tool to mode 2 (8gb) and one card to mode 0 and switched the cards to FDM 0…but the displaylink ports still wont output…is there a setting i missed in smi like the gom mode? Or is there a DP driver i need? I am working in a non networked location so im limited in pulling down drivers via internet.


Hello @minisandpirate and welcome to the NVIDIA developer forums!

Did you closely follow the instructions in the user Guide for the tool? There you will find which drivers are supported for which modes as well as the impact of setting FDM.

There might also be a typo in the docs where it states

Physical Display Ports Disabled with 64GB BAR1

A40 only has 48GB, so this comment does not make sense. I need to check, but the mode 2 might actually conflict with the A40 or disable DisplayPort support. Did you try without setting any gpumode?


I did notice the typo, but i do see when i select the mode its 8GB vs 64. And i have followed the instructions to the letter and in the smi it shows the cards are in WDDM mode but despite all of that plugging a displaylink cable into the GPU it will not turn on the display. I found switching it to mode 0 which is the 256MB Workstation mode the ports do show in the control panel but plugging a monitor in wont show. I did notice looking at the topology page it shows the ports are there but has no EDID file, is that something that is needed to turn the monitors on?

Thanks again

Roger Seeley

Well, yes, EDID is needed for the GPU to know the capabilities and timings of the attached monitor. I am surprised that you don’t see any.

I guess you have ruled out defective or too long cables?

I am a bit at a loss right now, I will try to get some more eyes on this, but no promises.

As to troubleshooting I would start from scratch and only use a single GPU to start with and get that to display. Only then start adding additional GPUs

I have tried cables of different sizes and no change… i have gone into the control panel and verified in fact the ports are showing. When i exported a edid file from a p1000 card and imported it into the a40 the smi shows the port is now on but it wont export. I am not sure if there is a generic edid file i could upload or one specific to the A40… one issue i have is since i work in a non networked environment i am limited in what i can do. It took quite a bit of time to figure out the initial issue with the cards themselves its just this last bit to get them to behave like a graphics card in a workstation setup.

On a side note does the same tool have to be used on Linux?