4 displays vs RTX 4090

[ascendence]

hey guys, i hope you can help me out

 

i cant have all my displays connected at the same time,

theres always some issue of some displays just not turning on at all, turning off for another one, etc

im most likely running out of bandwith:

 

basically i just want to have all my displays connected without crawling under my desk to constantly unplug and plug in displays

 

1x odyssey g9 5120x1440p 240hz

1x 1440p 75hz 

1x 4k TV 120hz HDR enabled

1x valve index 144hz

 

no i dont have an integrated gpu to run my 1440p display of off it

 

what are my options here?

is there some device that could help with sorting this out?

buying a low tier secondary GPU? 

[GOATWD]

1 minute ago, ascendence said:

hey guys, i hope you can help me out

 

i cant have all my displays connected at the same time,

theres always some issue of some displays just not turning on at all, turning off for another one, etc

im most likely running out of bandwith:

 

basically i just want to have all my displays connected without crawling under my desk to constantly unplug and plug in displays

 

1x odyssey g9 5120x1440p 240hz

1x 1440p 75hz 

1x 4k TV 120hz HDR enabled

1x valve index 144hz

 

no i dont have an integrated gpu to run my 1440p display of off it

 

what are my options here?

is there some device that could help with sorting this out?

buying a low tier secondary GPU? 

ok can you try runign the displays at 1080p and see if it hold s them all on

 

[ascendence]

31 minutes ago, GOATWD said:

ok can you try runign the displays at 1080p and see if it hold s them all on

 

i just tried

i could put all displays to 1080p at 60hz, but then turning on steamvr (to turn on my index) will make my pc instantly reboot

[AI_Must_Di3]

@ascendence You gotta keep all the combined displays under 7680 x 3840. This also hinges on which version of display port or hdmi youre using, the type of displays and the display lines youre using are certified for DP or HDMI and which ever version. Non certified wires may work but its a roll of the dice. So for example 1080p, which is 1920 x1080 will equal for 4 displays: 1920 x 4= 7680    1080 x 4=4320 .... so together thats 7680 x 4320 and it will sink your 4th display. Of course thats before you get to Hz and which hookup,DP or HDMI, and whether the wires are capable or not.

[ascendence]

46 minutes ago, AI_Must_Di3 said:

@ascendence You gotta keep all the combined displays under 7680 x 3840. This also hinges on which version of display port or hdmi youre using, the type of displays and the display lines youre using are certified for DP or HDMI and which ever version. Non certified wires may work but its a roll of the dice. So for example 1080p, which is 1920 x1080 will equal for 4 displays: 1920 x 4= 7680    1080 x 4=4320 .... so together thats 7680 x 4320 and it will sink your 4th display. Of course thats before you get to Hz and which hookup,DP or HDMI, and whether the wires are capable or not.

i understand that, hence why i said im probably running out of available or supported bandwidth, im just wondering how can i solve this issue buy a second gpu and have 2 displays on gpu1 and 2 displays on gpu2? just seems pricey and like a terrible solution

[TatamiMatt]

Are you running trying to run 1440p on all monitors for a specific purpose? Could you run one of the screens through the motherboard to take some load off the GPU?

[ascendence]

2 hours ago, TatamiMatt said:

Are you running trying to run 1440p on all monitors for a specific purpose? Could you run one of the screens through the motherboard to take some load off the GPU?

those are all the native resolutions of those panels, i do not have an i-gpu, its a ryzen 5800x it doesnt have an integrated gpu or else i would do that

[Glenwing]

3 hours ago, AI_Must_Di3 said:

@ascendence You gotta keep all the combined displays under 7680 x 3840. This also hinges on which version of display port or hdmi youre using, the type of displays and the display lines youre using are certified for DP or HDMI and which ever version. Non certified wires may work but its a roll of the dice. So for example 1080p, which is 1920 x1080 will equal for 4 displays: 1920 x 4= 7680    1080 x 4=4320 .... so together thats 7680 x 4320 and it will sink your 4th display. Of course thats before you get to Hz and which hookup,DP or HDMI, and whether the wires are capable or not.

This is incorrect, the "max resolution" spec on a graphics card is not added up between ports, every port is independent.

 

The issue is the GeForce cards only support 4 displays, and displays using DSC count as 2. The G9 at full resolution/refresh rate would require DSC.

[ascendence]

10 minutes ago, Glenwing said:

This is incorrect, the "max resolution" spec on a graphics card is not added up between ports, every port is independent.

 

The issue is the GeForce cards only support 4 displays, and displays using DSC count as 2. The G9 at full resolution/refresh rate would require DSC.

thanks for the clarification, do you have any advise what to do about it?

[Andrewtst]

5 hours ago, ascendence said:

1x odyssey g9 5120x1440p 240hz

1x 4k TV 120hz HDR enabled

Just only this two, it is near end and very difficult to added in the 3rd monitor in 1080p.

 

Nothing much you can do, wait for better GPU in future or run that Odyssey G9 @ 120hz.

[ascendence]

26 minutes ago, Andrewtst said:

Just only this two, it is near end and very difficult to added in the 3rd monitor in 1080p.

 

Nothing much you can do, wait for better GPU in future or run that Odyssey G9 @ 120hz.

what about running my 1440p screen off of a secondary gpu, like gtx 1030 for example? would that work?

[Andrewtst]

15 hours ago, ascendence said:

what about running my 1440p screen off of a secondary gpu, like gtx 1030 for example? would that work?

If your pc can insert 2 GPU, then I think no issue.

 

Now still got such design motherboard?

[AI_Must_Di3]

On 10/9/2023 at 11:32 AM, Glenwing said:

This is incorrect, the "max resolution" spec on a graphics card is not added up between ports, every port is independent.

 

The issue is the GeForce cards only support 4 displays, and displays using DSC count as 2. The G9 at full resolution/refresh rate would require DSC.

Incorrect?! So your saying because they are all independent line in's that they can run the max rez with all 4 displays at once? I agree that every port is independent. Why would a display using DSC compression count as two displays? As far as it goes, the card maxes out at 7680 x 3840, so how ever you want to arrive at that number is fine.

[Glenwing]

1 hour ago, AI_Must_Di3 said:

Incorrect?! So your saying because they are all independent line in's that they can run the max rez with all 4 displays at once? I agree that every port is independent.

Yes, it's incorrect. First of all, "Max resolution" doesn't actually exist as a restriction. GPUs have no restrictictions on the maximum resolution they will support except for those inherent to the protocol, such as a hard limit of 4095 in each dimension for old cards/drivers that only support legacy EDID or things like that.

 

This used to be easier to prove when "max resolution" specs were lower, for example Fermi cards like the GTX 580 listed "max resolution 2560×1600" but you can run 3840×2160 on it just fine (at 30 Hz due to bandwidth limitations of the connections it supports, but hey). On Kepler the "maximum resolution" was 4096×2160 but people ran 5K monitors on it just fine, and indeed, multiple 4K monitors (you see, the "max resolution" is not reached by adding up all your displays).

 

The "maximum resolution" spec was invented to give consumers confidence that their display would be supported. Back when 2560×1600 was the highest available resolution in a monitor, they liked to put "Maximum resolution: 2560×1600". But it's not meant as a "it can't go beyond 2560×1600", but more like "Yes it supports even those 2560×1600 monitors". These days, they generally just pick the highest standard 16:9 resolution that can be supported at 60 Hz, and list that as the "maximum resolution", but you can go higher if you lower the refresh rate, enable chroma subsampling or DSC etc., and it certainly doesn't mean that multiple displays are "added up" and checked against this number.

 

With modern cards having "maximum resolution" of 7680×4320 it's a bit more difficult to demonstrate from home than it used to be, but you can take it from NVIDIA instead. This was for RTX 30 series:

https://www.nvidia.com/content/dam/en-zz/Solutions/geforce/ampere/pdf/NVIDIA-ampere-GA102-GPU-Architecture-Whitepaper-V1.pdf

 

Quote

 Ampere architecture GPUs  can drive two 8K displays at 60Hz with one cable for each display.

As you can see, there is no "all your displays must add up to less than 7680×4320" limitation. You can run two 7680×4320 displays, one per port. The limit of two comes from the fact that DSC is required for 8K 60 Hz.

 

1 hour ago, AI_Must_Di3 said:

Why would a display using DSC compression count as two displays?

https://nvidia.custhelp.com/app/answers/detail/a_id/5338/~/using-high-resolution%2Frefresh-rate-displays-with-vesa-display-stream

 

[ascendence]

so i seem to be the only one that is in a situation where i managed to exceed the maximum bandwidth of my gpu?

[Glenwing]

9 hours ago, ascendence said:

so i seem to be the only one that is in a situation where i managed to exceed the maximum bandwidth of my gpu?

It seems to be a reasonably common occurrence:

 

https://linustechtips.com/topic/1509589-why-am-i-loosing-my-4th-monitor-to-dsc/

https://forums.tomshardware.com/threads/triple-samsung-ls28bg702epxen-monitors-are-stuck-on-120hz.3819333/

https://forums.tomshardware.com/threads/cant-connect-4-monitors-to-a-3090ti-gpu.3814708/#post-23056965