Date: Wed, 17 Aug 2016 16:37:19 -0400 From: Quartz <quartz@sneakertech.com> To: freebsd-questions@freebsd.org Subject: Re: Facing a strange problem Message-ID: <57B4CAFF.8030206@sneakertech.com> In-Reply-To: <VI1PR02MB09746A446A84576ABBF8F157C2140@VI1PR02MB0974.eurprd02.prod.outlook.com> References: <VI1PR02MB09746A446A84576ABBF8F157C2140@VI1PR02MB0974.eurprd02.prod.outlook.com>
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> CPU fan RAM What is a "CPU fan ram"? Do you mean you also swapped the RAM, or you put a fan on your RAM for some reason....? >the high-pitched noise (which resembles a bad > bearing turning furiously) Without being able to hear it myself, it's probably some form of transformer or inverter whine, or maybe something using PWM at low frequency. Anything with an electro-magnetic field oscillating at the right frequency will cause it. (This all assumes of course that what you're hearing is from the actual computer and not bad speakers or something). > The noise is most pronounced as I hover and move among the categories in > the gnome3 Applications menu. What's your CPU activity/frequency/clocking doing when this happens? Is there any other correlation to CPU activity? Is there a correlation to holding the mouse button(s) down? >I have no idea whether this has anything to do > with Radeon HD 8470D onboard graphics chip That's part of your new motherboard, right? Is your new board an identical model to your old one? Because if your old board had different hardware and you had the sound back then, its unlikely the new board would do the same thing. >the noise was not present when > I was running Windows XP with the correct official graphics driver. The sound is most likely specific to voltage/load in some particular circuit, which can vary due to all sorts of things. I wouldn't assume driver issues are the cause just yet. >If the > noise is related to graphics, then quite likely the source would be the > RAM modules - my system's video RAM comes from the main RAM. RAM doesn't make noise, like, ever. It's FAR more likely to be due to a voltage regulator or something feeding the graphics chip. > Other possibilities include the power supply unit Did your power supply cost at least $75 USD? Is it certified 80+ Silver or better? Because if not, then it's likely to be the issue, or at least a strong mitigating factor. Generic bargain PSUs are pretty notorious for producing atrociously "dirty" power, with all sorts of line ripple and EMF issues that cause weird problems like this. >I am currently ruling out the MB, CPU and CPU fan because all of them > are brand new. Again, are they identical replacements for your old ones? If so it might be an issue common to that model, or the combination thereof. I suppose the hard disk can also be ruled out it is a solid state > disk purchased just 2 months back. Does the machine make the noise when just looking at the BIOS (or BIOS equivalent)? If so, you can try powering it on without the drive. > Anyone who can help my identify the root cause Well, the "root" cause is electrical. If you don't have any moving parts besides your cpu fan, then some electrical field somewhere is vibrating the air at a frequency in the audible range, and that will be dependent on voltage/load. Then the question becomes what combinations of things you do with the machine that cause the issue to manifest. >would installing a separate graphics card > solve the issue ? The noise is extremely unlikely to be from your RAM, but you could try swapping around the hardware and putting in new cards anyway just to change the load on the PSU and different parts of the board and see what happens. If your new board is the same model as your old one, and the noise is due to the onboard graphics circuitry, using a separate card could very well make it go away. I'd also strongly recommend trying a different PSU too (regardless of quality, at least once just to make sure). Maybe try plugging all your USB devices into a PCI USB card or something if nothing else does it.
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