PC Display Is Noisy/Has Static While Rendering

[jt532]

I bought a GTX 1080 TI (EVGA SC2) on Ebay and I use it primarily for 3D rendering animations. This pretty much utilizes all of the resources of the GPU. Here's an example:

 

 

vs when it is idle, the "GPU load" section is 0%.

I have the card plugged into a monitor using an HDMI to VGA adapter like this picture:

 

 

where the HDMI side of the adapter goes into the HDMI port on the back of the graphics card:

 

 

and then I have another VGA cable going between the adapter and the monitor. I observed that while I am rendering, there is a fuzzy noise/static pattern that appears on the display. It is still usable, because it is fairly light and I can see everything underneath the static, but it is quite annoying. The noise disappears as soon as I stop the 3D render, and it appears instantly when I start the 3D render up.

If instead of using this adapter, I use an HDMI cable directly from the graphics card to the monitor, I do not see any noise. So I assume this is related to the fact that VGA is analog vs. HDMI being digital. What I don't understand is if this is normal behavior I would expect to see. Is there something wrong with the graphics card that is causing this? Is there something wrong with the adapter? Or would you always expect to observe this on modern GPUs since they draw so much power? I'm just trying to understand why I'm observing this.

[jt532]

4 minutes ago, billbill said:

I'm going to assume that since HDMI carries both audio and video and VGA carries video using the adapter is causing the noise. 

So why do I only see the noise when I'm doing a 3D render but not otherwise?