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Possible coil whine in my nMP

Hey BJonson, I hear what you're saying. I've had the exact same problem in MacBook Pros and in my iHack. Turning off the C1 states usually fixes this kind of whining. I have ran a Cinebench CPU benchmark yesterday and listened for changes in the noise the nMP makes — it stays consistent. I'm inclined to say that CPU power state toggling is not the culprit here but I could be wrong.

In my Hackintosh days I've gotten involved with kernel extension changes quite a bit but I haven't found any power states in the ACPI/CPU/SMC related kexts that I know of. There was a thread on Apple Discussions where someone fixed his MacBook Pro whine by tweaking the ACPIPlatform.kext. The corresponding values aren't there though on the Mac Pro.

I think I will order a replacement machine from Apple and look for other solutions in the mean time. Maybe this is just a case of bad luck. I fear it's not though.
 
BJonson said:
My thinkpad makes this exact same noise. The fix is to turn off CPU low power state in the bios. Intel CPUs sometimes make this sound when they are trying to lower the voltage in the multiple cores. The fix works on the thinkpad but not completely, it lowers the sound to a very quiet undetectable level but its still there. Only seen this in sandy bridge and ivy bridge though. I think the nMP uses ivy bridge right? I know its not haswell.
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It uses Ivy Bridge EP. The haswell cpus in that socket are not out for some time.
 
Yes, old PowerBooks had this issue related to CPU idling too. And I have noticed it on my 6c d700 as well. Though I don't think it's constant. Only under certain loads.
 
I can reproduce some sort of coil whine coming from the main fan at a certain RPM.

Try downloading Macs Fan Control
http://www.crystalidea.com/macs-fan-control

Change the main fan from "auto" to "constant rpm" and play with the settings. Don't put any extra load on the GPU's.

Mine starts making some sort of extra noise at around 1020 - 1035 rpm. When I increase it to 1050 rpm the whining is gone - just light fan noise.
 
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0x2102 said:
I can reproduce some sort of coil whine coming from the main fan at a certain RPM.

Try downloading Macs Fan Control
http://www.crystalidea.com/macs-fan-control

Change the main fan from "auto" to "constant rpm" and play with the settings. Don't put any extra load on the GPU's.

Mine starts making some sort of extra noise at around 1020 - 1035 rpm. When I increase it to 1050 rpm the whining is gone - just light fan noise.
Click to expand...

Tried this before and I'm sorry to say that my nMPs noise seems to be entirely unaffected by the fans rpm.

I was hoping that I was unlucky with my machine (well, both of them), but it seems like more and more people are joining this "coil noise"-club? I'm not hopefull anymore concerning my replacement 6c,D700,32GB,512GB which will arrive in a month or something. Also, the fact that I will be without a nMP for at least a month makes me an unhappy camper right now. I should start preparing a hush-box or something...
 
I have a feeling they will all whine its just some people cannot hear it or tolerate it more. Ill let you know when I get mine.
 
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0x2102 said:
I can reproduce some sort of coil whine coming from the main fan at a certain RPM.

Try downloading Macs Fan Control
http://www.crystalidea.com/macs-fan-control

Change the main fan from "auto" to "constant rpm" and play with the settings. Don't put any extra load on the GPU's.

Mine starts making some sort of extra noise at around 1020 - 1035 rpm. When I increase it to 1050 rpm the whining is gone - just light fan noise.
Click to expand...

If that is the case, some folks not hearing it might be due to ambient room temps.. either fan at default is slower or faster than what's needed to generate it..

IF it is the fan...
 
richard371 said:
I have a feeling they will all whine its just some people cannot hear it or tolerate it more. Ill let you know when I get mine.
Click to expand...

Kinda sucks for such an expensive machine. I've had many computers and this is the first time I've ever heard such a noise that really bugs me out. I primarily work as a system administrator, and manage about 200 computers at work, and there I've had some laptops with noise-issues, and some screens with strange noises, but I never expected it from the nMP. Today I took my MacBook out of the room, and sat in another, quiet MacPro-free, room.

Though, all things considered, it is a really beautiful machine!
 
mine just arrived, so I'll see if I hear it.. of course, I might not over my Tinnitus.. :rolleyes:
 
tylmad said:
Kinda sucks for such an expensive machine. I've had many computers and this is the first time I've ever heard such a noise that really bugs me out. I primarily work as a system administrator, and manage about 200 computers at work, and there I've had some laptops with noise-issues, and some screens with strange noises, but I never expected it from the nMP. Today I took my MacBook out of the room, and sat in another, quiet MacPro-free, room.

Though, all things considered, it is a really beautiful machine!
Click to expand...

It might be interesting to figure out (if that is even possible) if this issue is applied to most nMPs or it is only on few pieces. For instance, what about the nMPs used for demo machines in Apple stores ?
 
antonis said:
It might be interesting to figure out (if that is even possible) if this issue is applied to most nMPs or it is only on few pieces. For instance, what about the nMPs used for demo machines in Apple stores ?
Click to expand...

Well, when I hold my iPhone over the MacPro, towards to outlet, as close as it gets, I can make a recording where the noise is clearly audible. Maybe we can make some recordings of our machines and compare them?
 
Ok I tried it on my iphone cranked up and can barely hear it. Im sure they all do it if the conditions are the same. I will just have to see if it bothers me when I get it or if the other ambiant noise drowns it out.

Can anyone remove the cover and try to pin point exactly where its comming from?



saschke said:
Absolutely. Here's mine, taken with the iPhone 5s mic. http://cl.ly/2V47190Q2f3R
Click to expand...
 
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If you can't hear it on In-Ear studio monitors or even Soundsticks or something of that quality, consider yourself lucky ;) The built-in monitors will most likely not be able to reproduce such sounds.
 
Would prob be hard to hear in the store.

antonis said:
It might be interesting to figure out (if that is even possible) if this issue is applied to most nMPs or it is only on few pieces. For instance, what about the nMPs used for demo machines in Apple stores ?
Click to expand...
 
The people that have this whine where are you located? Running 110 or 220 volts?

Obviosly the amount of cores, GPU model doesnt seem to matter here from what I can tell.
 
I'm in Germany. We have 220V outlets here.
@richard: I think it's not possible to run the machine without its cover. Or has someone clever found a way and posted it online?
 
There are many variables, some of which are subjective.

How about using a spectrum analyzer to isolate the offending sound. Something like this might work:
http://www.dogparksoftware.com/iSpectrum.html

It seems like comparing the frequency or magnitude of parts of a graph would be easier then listening to sound files.
 
Ah didn't realize that it would not run without the cover but it makes since for the proper airflow.

So it looks like 220V so far are reporting this issue. Will be intersting to see if anyone on 110 notices it.

saschke said:
I'm in Germany. We have 220V outlets here.
@richard: I think it's not possible to run the machine without its cover. Or has someone clever found a way and posted it online?
Click to expand...
 
saschke said:
I'm in Germany. We have 220V outlets here.
@richard: I think it's not possible to run the machine without its cover. Or has someone clever found a way and posted it online?
Click to expand...

The inside of the cylindrical case has a small magnet, at the same height from the base as the power button. I'm sure that apple disapproves, but I guess you could tape a small magnet there instead and then run the computer with the case of. The cooling sinks are located in the centre of the machine, and the fan is pulling air through them, so I don't think that the cooling would be affected in any large way. But I haven't tried it.
 
An additional thought on this...

I've experienced coil whine on different occasions including a 7950, multiple PC motherboards, and power supplies. While I was never able to address the issue with a faulty power supply, I was able to eliminate the coil wine by increasing voltage settings within the firmware of the 7950, and adjusting voltage settings within the bios settings of the motherboard. I'm not talking a huge increase, only a small increase of several tenths of a volt.

As the 2013 Mac Pro does not have access to adjust voltage is within the user-interface, it would be possible to modify at least the video card firmware within the EFI updates available for the nMP. I have seen the details over at Netkas.org illustrating the voltages settings for the D300, D500, and D700 GPUs, All of which are greatly less than their PC equivalent counterparts.

In theory, the coil wine you are exposing may be a result of apples need to deliver lower voltages to components to meet the requirements of what may be a less than adequate power supply system.

Now, getting Apple to adjuster voltages on the new Mac Pro , if it ever happens, will probably take many months. For example, when playing MP3s on the 2009 Mac Pro, the CPU would quickly escalate to near 70°C with hardly any CPU activity. It took Apple close to six months to fix this issue. Additionally, there have been issues with AMD video cards supporting 4K @ 30hz. I first reported this to Apple in mid November and here we are in March with the release of 10.9.2 and a fix is still not insight.

Good luck! I hope the information helps. I now return your tree right to regularly scheduled program.
 
richard371 said:
Ah didn't realize that it would not run without the cover but it makes since for the proper airflow.

So it looks like 220V so far are reporting this issue. Will be intersting to see if anyone on 110 notices it.
Click to expand...

Or a user with 220v mains tries it with a 110v stepper transformer. We are 240v here in the uk and I have had no client bring this whine issue up so far with a nMP.

Just got off the phone to my pal who is a genius with RF and switch mode power and currently has a nMP in pieces to study(!). He reckons there's a single coil that's loose inside and oscillating making the noise in the PSU at 220v. Seconded too that the 220v users try a 110v stepper transformer.
 
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Long time lurker, figured I should pitch in with some additional info.

I've now tried two 6c, D700 machines and they both exhibit intense coil whine. While idle it's almost bearable, but moving the mouse(!) or doing something GPU heavy and it whines like a cat.

To me it seems like this is either a problem with the components used (or a specific batch) or the manufacturing process.

I live in Sweden, so voltage might be an issue.
 
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So far it appears only to be 220v users.

tozz said:
Long time lurker, figured I should pitch in with some additional info.

I've now tried two 6c, D700 machines and they both exhibit intense coil whine. While idle it's almost bearable, but moving the mouse(!) or doing something GPU heavy and it whines like a cat.

To me it seems like this is either a problem with the components used (or a specific batch) or the manufacturing process.

I live in Sweden, so voltage might be an issue.
Click to expand...
 
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