Comments on: Simple Display Emulator with an HDMI-VGA Adapter

By: hlide fremen

hlide fremen — Thu, 27 Jul 2017 07:31:37 +0000

So, if I understand well, this trick allows a second GC to be used only with OpenCL or Vulkan because those API can let us select which device to compute with, right? This trick is in no way a solution to make OpenGL using the second GC, right? If I’m not mistaken, you need to set the primary screen on the monitor plugged on the right GC to run OpenGL upon it – something not confortable to deal with.

By: Stefan

Stefan — Tue, 25 Jul 2017 15:13:25 +0000

In reply to Salman. You might cause a short circuit that can destroy hardware. So let it be done by s.o. who knows what he is doing.

By: Salman

Salman — Mon, 03 Jul 2017 07:10:03 +0000

No way is this trick gonna work?
What if I put the pin in wrong hole with wrong resistors.

By: JeGX

JeGX — Fri, 16 Jun 2017 16:53:53 +0000

In reply to ramg. You can buy 1/4W (0.25W) or 1/2W (0.5W) resistors. 0.25-watt resistors are fine for this use.

By: ramg

ramg — Fri, 16 Jun 2017 03:52:51 +0000

i want to try this but when i buy resistors they asked me the wattage. pls help.

By: MrDeprecated

MrDeprecated — Tue, 13 Jun 2017 07:24:26 +0000

In reply to MF. "There is no way to tell Windows OpenGL should NOT be handled by the graphics card connected to the primary monitor." Yep, exactly what I was thinking =)

By: MF

MF — Mon, 12 Jun 2017 13:35:07 +0000

Correct, but this is what Windows does when you have 2 graphics cards, 2 monitors and with *each* graphics card connected to a monitor.

Windows has the concept of primary monitor that you define in the display properties.

From there, the OS looks at the graphics card this monitor is connected to. This graphics card will handle OpenGL. It will also dynamically send the frame of the second monitor to the second graphics card for display. Basically, the first graphics card has an internal FBO which size is the display size of the monitor connected to the second graphics card.
The FBO contents are then blitted over to the second graphics card in realtime.

On my computer, I have my primary monitor set to my GeForce GTX 980, and my second monitor is connected to my Intel Skylake adapter. So the Skylake adapter receives its display contents from the GeForce in realtime.

And I can change the primary monitor if I want to test my OpenGL programs on Skylake. It’s that simple.

Here, your scenario is different, unfortunately.

There is no way to tell Windows OpenGL should NOT be handled by the graphics card connected to the primary monitor.

By: MrDeprecated

MrDeprecated — Mon, 12 Jun 2017 09:58:29 +0000

In reply to MF. I don't think so, because you gonna have to find a way to redirect the information which graphics card B has to graphics card A. Assuming that graphics card A has monitor attached to it. This will involve may be a lot of driver and OS wizardry/trickery just to get it to work? But again, I might be wrong xP

By: MF

MF — Sat, 10 Jun 2017 09:57:25 +0000

Is there a way to have OpenGL (not OpenCL) run on the “dummy” graphics card but with the display still redirected to the monitor connected to the master graphics card?