Second monitor interference when graphics card is under load

[Protec]

I noticed that when my GTX 750 Ti is under load, the second monitor gets interference. Anyone know what could be causing this? My best guess is failing caps.

 

Note, second monitor is connected using VGA, main monitor is connected via HDMI.

[3s-gtech]

On VGA, the second monitor will be running through a DAC which will be sensitive to voltage. Your PSU could be a problem, as much as the GPU itself. The 750Ti is not a big power draw - that was one of their big positives.

 

First port of call though - try another VGA cable!

[Protec]

On VGA, the second monitor will be running through a DAC which will be sensitive to voltage. Your PSU could be a problem, as much as the GPU itself. The 750Ti is not a big power draw - that was one of their big positives.

 

First port of call though - try another VGA cable!

 

Thanks! The 750Ti is the Asus version with the 6 pin power input. The PSU I'm using is a Corsair VS350 which is about 4/5 years old I think. I will have to try another VGA cable. I think it was from an XP machine and is VGA with the audio cables integrated but they are chopped off.

[3s-gtech]

Decent brand, and even with most desktop processors 350 watts will still be enough.

 

I’ve had so many issues with old VGA leads into monitors and projectors - straight swap and the issue is gone.

 

Why it would manifest under load - perhaps the card or another component produces more EMI, earthing is poor, or similar.

Edited July 25, 2021 by 3s-gtech

[Protec]

Decent brand, and even with most desktop processors 350 watts will still be enough.

 

I’ve had so many issues with old VGA leads into monitors and projectors - straight swap and the issue is gone.

 

Why it would manifest under load - perhaps the card or another component produces more EMI, earthing is poor, or similar.

 

I do wonder if there is some sort of earthing issue. When I plug in the VGA cable, there is always a small spark produced - it sometimes causes the GPUs fans to ramp up to full speed until the PC is restarted for some reason?. I have had small shocks off the 3.5mm audio cable too. It's a strange thing to happen since everything is supposedly grounded or double insulated. However, the sparking issue doesn't seem related to the interference and as you say, I'm not sure why that would change with load. It's also worth mentioning that the GPU seems to suffer from coil while. When "moving" in game the pitch of the coil whine changes. I'm pretty sure its coming from the GPU and not the PSU.