2nd gpu monitors not showing to capture, but show up for fullscreen display (preview)

[JCWOLF]

2nd gpu monitors do not show up on the list of displays to from capture,
but do show up on the list of monitors for fullscreen display (preview).

Swore they showed up the other month when testing the new graphic cards
manycam shows all monitors from both gpu's available for capture
obs only shows GPU0 monitors for capture
but
obs does show GPU0 & GPU1 monitors for displaying fullscreen (preview)

is there a older version of obs known that'll show both gpu's for capturing
or can we please have options to fix this in a bug fix for this soon?
thanks

 

[FerretBomb]

OBS cannot capture displays that are not connected to the GPU it is running on. This has always been the case. There is no older version where it works.

To capture a non-connected display would require constant transfer over the PCIe bus (potentially to the point of flooding it) to load the desktop texture into VRAM; cross-GPU support as a result is a very low-priority feature request, last I'd heard, and may be unlikely to be implemented by the main dev team any time soon.

 

[JCWOLF]

Thanks
Though with these rigs, it's far from flooding my bandwidth, nor any of the resources while recording/streaming by Manycam 7.5.1.5, I can't afford manycam for each rig 8( heh plus manycam doesn't have a night mode 8P nor does it have a backend to mod like OBS.

It shows preview presets from all 5 monitors on both GPU0 and GPU1 to switch between with another 7 presets of follow cursor, or locked area's of displays being showed (no matter the GPU their using) on designated monitors and HDMI capture card feed.

All showing nicely thru Manycam's video preview from the all monitors GPU0, GPU1 and capture card, and not even breaking a 20% utilization on CPU, CPU-MEM, GPU0, GPU1 & their MEM. I only hit 90% when running multiple windows of programs, and resource hog games do i crack 90%, and still unable to see signs of slowing down to the eyes, while recording and streaming.

So either manycam is doing voodoo magic, or obs needs to take notes from manycams hardware abstraction layer methods for copying memory around.
Thanks for the reply, BF

 

[FerretBomb]

Thanks
Though with these rigs, it's far from flooding my bandwidth, nor any of the resources while recording/streaming by Manycam 7.5.1.5, I can't afford manycam for each rig 8( heh plus manycam doesn't have a night mode 8P nor does it have a backend to mod like OBS.

It shows preview presets from all 5 monitors on both GPU0 and GPU1 to switch between with another 7 presets of follow cursor, or locked area's of displays being showed (no matter the GPU their using) on designated monitors and HDMI capture card feed.

All showing nicely thru Manycam's video preview from the all monitors GPU0, GPU1 and capture card, and not even breaking a 20% utilization on CPU, CPU-MEM, GPU0, GPU1 & their MEM. I only hit 90% when running multiple windows of programs, and resource hog games do i crack 90%, and still unable to see signs of slowing down to the eyes, while recording and streaming.

So either manycam is doing voodoo magic, or obs needs to take notes from manycams hardware abstraction layer methods for copying memory around.
Thanks for the reply, BF

I believe that Manycam does its rendering/composition in system RAM by CPU, with minimal (if any) capability to overlay or add multiple sources to a composited scene; OBS handles everything in VRAM instead with GPU acceleration, which scales MUCH better in a situation that may have truly massive numbers of sources and effects to layer and composite. OBS has to do this, because it can do so much more than Manycam.

Also, not saying that they couldn't add support, or that it would affect your rig. Mine would be fine too. But the guy trying to stream from a U-variant i3 (or Pentium) laptop with an Intel IGP? Yeah, it'll mess him up but good. And generate more support requests/hassle, because when it messes him up, he won't know why. For a very niche segment of the user-base (multi-gpu systems, aside from laptops)? They just have larger features to address and add that will benefit a wider part of the total OBS community, and an already-overfull plate of those.

Up side, OBS is open source! If you've got the spoons to get this implemented, I'm sure that Jim and the rest of the dev team would be happy to see a pull request adding it as a feature. Until then, OBS may simply not be the tool you need, even if it is the free alternative.


Side-option/workaround, you can run a second copy of OBS in Portable Mode on the second GPU at the same time (ignore the 'obs is already running!' warning), install the obs-ndi plugin on both, then assign NDI Output filters on each display-cap on the OBS PM instance for the second GPU, then catch them with NDI Sources on the main OBS instance for integration and inclusion into your scene. Since it's all on-system loopback and not over the network, impact really should be minimal. With OBS, creative use of existing features can get you far. :)

 

[KrisSmith]

I think this is the Same "problem" I am having.

OBS cannot capture displays that are not connected to the GPU it is running on.

In which case How do I get OBS running on a different GPU?

 

[FerretBomb]

I think this is the Same "problem" I am having.
In which case How do I get OBS running on a different GPU?

The following link applies to multi-GPU desktops as well as laptops. Please note that multi-GPU desktops are NOT a good idea for streaming purposes. At best you'll split your PCIe lane allocation, and OBS needs that speed to transfer per-frame source data to the active GPU.

Laptop GPU Selection Windows 10

OBS Studio - Free and open source software for live streaming and screen recording - obsproject/obs-studio

obsproject.com

If you are on a Desktop, make SURE that ALL of your displays are connected to your GPU, and not any video port included on the motherboard's I/O shield. You will gain none of the hardware acceleration of a dedicated GPU, if a monitor is plugged in there.