[SOLVED] NVIDIA 4090 with 4 outputs?

eight

Could anybody share a working video commutation setup with NVIDIA 4090? Mine has 3 DisplayPort and 1 HDMI outputs, and I'd like to feed one control monitor and three projectors (all 60Hz, 1080p), which all have HDMI inputs.

So, I am looking at 3 display port to hdmi adapters plus one straight hdmi cable. I just got one DP–> HDMI adapter to test and it's no good for DP–>HDMI conversion.

Are there proven DP–>HDMI adapters for NVIDIA 4090?

Would not hurt to mention that I am using hdmi optical cables 30 and 40 m long.

Thanks!

CitizenJoe

@eight

This may not be helpful if you already have the HDMI cables, but I'd suggest DP -> SDI using the Blackmagic or AJA converters. Run SDI as far as you can and straight into the projector if possible, or convert at the projector. There's a bunch of DP -> SDI options on Amazon, too, but I've not used them.

To better address your question, the GPU shouldn't make any difference to the converter, but I wonder if the optical cables do? Have you tried using that same converter with a short regular HDMI cable into a TV? Then into the Projector? Etc.... It may have something to do with the length of your cables, which is long for an HDMI signal.

Finally, try changing the refresh rate of the output signal. You may find that it works on one and not on another.

Hope this helps!

Cheers,

Hugh

dbini

As far as I know, DP-HDMI should be a straightforward conversion - just changing the plug shape, so if a DP-HDMI adapter works with one set-up, it should work with any. Does DP have the same handshake system as HDMI? I only ever used DP with DVI-D, or MiniDP with HDMI and assumed that the signals were pretty universal.
Optical HDMI cables should be fine over those distances, which would be too far for copper HDMI.
As Hugh suggests, you need to trace this issue by testing one thing at a time - is it the settings on the GPU? the adapter? the cable? the settings on the projector?
Hugh's suggestion of going SDI is also good - and should be future-proof, but in your situation, it may need too many adapters. If the projectors are not SDI compatible, than you would need DP-SDI, then SDI-HDMI at the other end. Blackmagic kit is cool, but I would be wary of cheap HDMI-SDI adapters. I bought a set a few years ago to try to solve the problem of long HDMI runs, but it turned out to be a little unstable. I haven't used it since I swapped my regular HDMI cables for optical HDMI cables.

Gaspar

@eight

Hi, I would also know about "proven" adapters.

I have two different miniDP to HDMI adapters: A Hama and a no brand. Hama works on my 4K monitor the No brand works also but only at 1080.

At different venues I need to connect to many different projectors. Sometimes the better adapter does not work, but the other one does. It even happened to me using different HDMI inputs of a same projector or using different "long" HDMI-Projector combinations.

I'm trying to make the point that I could not find out any logic allowing me to predict which of the adapters will work when. So, if you plan to usually use the same cables and projectors you might be fine with with just one kind of adapter. I'm happy having two different ones.

SDI is probably the most robust solution, certainly for long runs. However you might find some configurations where those conversors might fail as well.

Fred

@eight both Display port and HDMI have a variety of versions. Various devices, extenders and adaptors may not play nice with each other. In my experience this is mostly due to cable quality and then adapter versions (eg currently hdmi is at 2.1b). Display port has similar variations and DP to HDMI adaptors will go from a specific set of DP versions to a specific set of HDMI versions. Mixing these on a single video card can give you errors.

The other common issues are slight timing mismatches, these are technically within spec but sometimes cheap extenders use a close enough timing that is not recognised by the receiver. Colour space mismatch is another common issue.

I have used HDMI -> SDI and SDI -> HDMI extensively to and from countless devices and had almost 0 problems as long as the cable is to the correct spec. This limits you to SMPTE resolutions but it’s so reliable, as you are only using short HDMI and no “clever” HDMI over fibre.

For non SMPTE resolutions go for for HDBaseT, it is a professional recognised standard (built in to many Panasonic projectors). Again it needs to be run over the right cable and you you need the right HDMI version support for some resolutions.

The great thing about using these is that a venue can almost always supply the long cable. If they don’t have it it costs them nothing to rent and it’s an easy addition to the rider. Just ask for the exact right cable spec (cat 7 sftp, 12g sdi or whatever you need for your resolution). This makes touring so much easier as you only bring the reliable converter kits you know work with your gear. The house only supplies a cable of a known measure able standard.

To debug your setup you will need to break things down one at a time. I have used club3d dp to hdmi converters with great success. They actually tell you the version support clearly on the product page. Unsurprisingly you get what you pay for and the high spec costs more.

eight

Thanks everyone for your enriching inputs. For now, I ended up with a no name one directional Dispaly Port DP 1.4 M to HDMI 2.1 F, 8K, similar to this: https://arwall.co/products/8k-...