I recently upgraded the following system with a 2nd graphics card.
CPU: i5 2550k
Mobo: Gigabyte GA-Z68X-UD3-B3
RAM: 8GB Corsair Vengeance Red 1600Mhz
1st GPU: Zotac GTX 550 ti 1Gb
PSU: 600W PC Power and Cooling Silencer MKIII
The card I bought was a EVGA GTX 550 Ti, and quickly installed it into my system plugged everything in and powered on my system.
I don't think this is relevant but on the initial boot, the system started for a second then stopped for a few seconds and started again. I assume this was due to it identifying the new hardware.
Anyway once it booted into windows and installed the drivers, I restarted so I could turn on SLI then proceeded to play BF3 as a test for temps, FPS etc.
But as soon as any 3D rendering occurred my system started making an awful high pitched squealing noise.
I thought it could have been fan whine, but I raised both cards fan speed as high as possible in MSI afterburner and let them drop back to normal speed and couldn't hear the noise.
I changed the clock speeds of the slightly overclocked EVGA card to stock clocks to match the Zotac's but the noise was still there.
I have done some experimenting and the noise is significantly louder when the GPU is being used more, being loudest in MSI Kombuster and BF3. I even ran MW2 with VSync on and changed between looking at the floor and looking at busy scenes and the noise correlated with the GPU usage reported by MSI afterburner and me looking at the more detailed scenes.
Another oddity is that when the EVGA card is plugged in but I have disabled SLI the noise is there, yet when the second card is not present the whine vanishes.
I have unplugged and replugged everything but to no avail.
I have heard that this may be due to the coils that regulate the power having to work hard, but am not sure whether this is true for my system, though they did say that is wasn't damaging.
My main concern is damaging the card, rather that the noise as I use a headset mostly in-game and can generally deal with background noise.
Any help you can give is much appreciated and I'll do my best the try out your suggestions and be happy to provide more info when needed.
When it is not your fans or the power supply then it is always inductor noise. I suggest that you return the card or to modding it. R30 rated inductors should be safe and maybe you could try to isolate which exact inductor is giving off the coil squeal.
I had a go at identifying the card that was making the squeal and it was the Zotac one, which was my first card that i had zero problems with before adding the EVGA. I will try the zotac on it's own without the EVGA even in the system and see if the noise reoccurs.
First and foremost thank you for your thoughts and replies.
I now am pretty sure that the noise is coil whine, the reason I didn't mention it was because I thought coil whine was caused by the fans and only accidentally found that it was the cause of my noise from a LinusTechTips video on mobo coil whine.
Furthermore I am sure that this noise is not a recent phenomena, but one I have had a while. When I installed my second GPU, I put the case on the desk and left the side panel off. This meant that my right ear was directly facing the components and I could hear the noise very audibly, especially as I did not have my headphones on nor were my speakers very loud.
Upon putting the side panel on, removing the 2nd GPU and putting the whole tower under my desk (like before) I have found that I cannot hear the coil whine, unless everything is muted.
Therefore I only have one question left, is the coil whine damaging or should I be fine considering I am not going to overclock etc.
At first it will only be a noise issue but over time the coil will get weaker and less power will come from the affected vrm phase. Given the coil type it will get very hot and act as a small heater coil than anything else. The other type that is common to high end cards like the 580 it shorts out then breaks the circuit so the vrm phase doesn't provide any power to the gpu.
As for your card I would keep a close eye on it and if the plastic begins to change color or shape you will need to replace it. If the hot spot on the back of the card where the bad coil is has anything like a mosfet or a cap in or near the bad coil it will cause problems down the line. The caps get warm on their own when under full load.