Trying to learn

Hello everyone

I am just starting to learn, so please bear with me.
GPU in a video card is a DAC right? Converting digital signals into Analog signals, so they can be displayed on the monitor. Am I correct in this simple breakdown?

If so. Can the gpu be reversed into a ADC. To convert Analog signals into Digital signals?

This is outside my area of expertise. Back when video signals were analog, graphics cards contained a DAC (either integrated in the GPU or as an external device in the days before GPUs). Nowadays, video signals are digital, so I do not think there are DACs in modern GPUs.

Independent of the use of DACs in graphics cards a DAC is not simply reversible into an ADC. At best you could construct a ADC mechanism that utilizes a DAC as one of its constituent parts. For example, use a counter, a DAC, and a comparator: feed counter output to DAC, compare resulting voltage from DAC to input signal, stop counter from incrementing when output from DAC exceeds input voltage. The counter value thus represents the input voltage. You would need additional electronics to construct such a feedback loop to achieve ADC functionality, but a DAC integrated into the graphics card does not offer such additional circuitry.

Thank you for that informative reply njuffa.

I got the idea of a gpu having or being able to simulate both a ADC and DAC internally. From my limited knowledge I ran the operation of the video card in my head like this.

The graphics going into the video card from any software is digital and would need to be converted to an analog video to be displayed on the monitor. That is if the monitor is RGB/VGA, or if the video card had a RCA output.

I must be wrong in thinking GPU is built with internal ADC and DAC.

Hello Nicholas.

I still see video cards for sale with vga and rca/svideo out.

Now that you mention it, a capture card is what it sounds like. Your comment made me look to see if nvidia ever made a capture card, and they did. So it is possible to make a gpu convert analog signals into digital.

I see nvidia has some info about gpu direct for video. I am going to read up on it. Anyone know where to get gpu datasheets¿¿ Not the advertisements nvidia calls datasheets.