My brand new Dual 2.3 'chirps' when I resize windows, drag windows, etc. I've read about the CHUD tools NAP fix, but I hear it's "not reccomended" by Apple. I guess I'm also in the same boat looking for a permament fix.

This chirping thing, does it actually come from the tower itself or is it a beeping sound through wav files or something like that on the desktop?

It sounds like an electronic chirping sound that emits from the tower everytime certain actions are performed. It does not make the sound when the computer just sits there idle.

There is also a pulsing sound that comes from my G5 dual 2.3. It is not loud but quiet annoying.

I believe this is an issue on most if not all PM G5s. From what I read online, it's the power supply that's making the noise, and it's caused whenever you have Nap mode on. Nap mode allows the processor to sleep whenever it has an idle cycle.

Now, the chirping noise only seems to appear whenever you resize a window, scroll a window, do anything OpenGL, etc, so I believe it might have something to do with the way the CPU and video card interact.

All I know is that the chirping noise is evident on my week-old DP 2.0 rev.C. Downloading CHUD tools and unchecking the Allow Nap box fixed the noise, but it didn't stick on a reboot, and isn't recommended by Apple. For now, I put my PowerMac on the floor next to my desk, and I really can't hear it unless it's in the dead of the night. But when I can hear it, it's like there's a little kitten scratching subtly on my ear drums, if that makes any sense. In other words, it gets very annoying, very fast. And this is coming from someone who switched from a (very!) noisy Athlon64 box. But other than that, my G5 is nearly silent.

My RevB DP2.0 rarely has it. sometimes when playing QT movies in the preview column. But it has been a while now since I heard a chirp come from it. Nothing has been changed.

I'm not convinced that it's quite as simple as just a power supply defect. My new PowerMac didn't chirp at all, but then I had to get the mainboard replaced by AppleCare and now it does. Same power supply before and after.

The chirps seem related to bus activity, specifically when the video card is moving lots of data. The RSS screen saver makes it chirp, or playing games in full screen mode. Less so with windowed tasks, although even then sometimes it chirps a bit if the window is "busy". (World of Warcraft, in particular)

It's a quiet noise that you might not even notice, but it's hard to not focus on it after it bugs you the first time. I just use the "NAP" trick whenever I'm about to do something that I know will make it chirp. It's easy to enable/disable NAP via applescript, which is simpler than launching CHUD Tools all the time.

FYI, my friends PC also chirps. Seems to be gfx related - so any time you resize a window etc...

I just got my PM dp2.0 yesterday. No chirping that I can detect. I've got the unit on the floor, but fairly close by. The only thing I hear are the disk drives accessing.

(I sure had a LOT of difficulty installing RAM modules! Had to reseat them three times before the system saw them. Not a lot of room in there for hands, either.)

its the cpu, it happens on my powerbook also...

And can you hear a pulsing sound that comes (I am not sure) from the 2 main fans in front of the processors ? It makes a kind of "woo woo woo" sound ...

You did take out the intake fans I hope, there's plenty of room, and it should be fairly easy to install...

Yes. But I have big hands ...

I've been having the chirping also. Got my PM last week. I'll be more aware now but I really notice it while playing WoW (World of Warcraft).

Nugget - I'm new to the Mac, how do you do an Apple Script to turn off Nap? (And back on I would assume). Also was wondering if when you play WoW if it is laggy. Game looks beautiful on my 23" ACD but laggy. I've tried tweaking the video settings but doesn't help.

J.

You'll need a hefty video to run WoW successfully at higher settings.

Anyway, I also think the chirping is graphics-bus related. Does anyone know exactly what disabling NAP does? That solves the problem for me, but if it means that my PowerMac might run hotter or make my electric bill go up noticeably then I can live with the chirping. I just might take it in to the Apple Store soon and see if they can do anything about it.

I talked with two guys today at the apple store. A sales guy and one of the genius bar guys. They both said they have never heard the "chirping" before. They gave some things to look at but I had already checked those things out. They asked me to try to narrow down when it occurs and maybe lug in my PM.

What type of hefty video do I need? I have the ATI Radeon 9600XT with 128MB VRAM. And my system is running 2.5GB of RAM. My laptop only has a 64MB video card and a gig of ram. I only lag when on dial up.

J.

Just found this out and thought it was kind of strange. I was playing WoW and put it in windowed mode (command + M), and the chirping is not nearly as loud or as frequent in windowed mode. Also, sometimes when I have another window other than the WoW window active, the chirping goes away, and then as soon as I click on the WoW window, the chirping comes back, even though the WoW window is still fully visible, just not active. This would lead me to believe that the chirping is related to graphics, and can be fixed.

I just finished a two hour WoW session and the chirping was going on almost the whole time. Now with it closed and just Firefox up, the sound is gone. Looks like it is graphics related or at least when the computer is crunching away. Going to do some Photoshop and test renders in Lightwave to see if it chirps then.

J.

My chirping sounds more like a hamster wheel with the hamster going full bore on it! It gets quite loud at times, and has nothing to do with intensive apps like Doom 3...

I called Apple care twice on it, all they could say is to take it into the local service center... hate to do that without a definite fix in mind first though!

I've got the GeForce 6800 Ultra card and WoW beautiful and smooth in 2560x1600 on my 30" cinema display with all the settings cranked to the maximum. On my old PowerBook G4 I have to minimize all the graphics settings to the bare minimum and even still it's kind of choppy at times.

It's possible to enable or disable NAP from the command line or from an applescript. In Terminal.app you can run the command using true or false as required:

code:

---

hwprefs cpu_nap=true

---

Similarly, you can do this inside applescript (fire up Script Editor and create a new applescript):

code:

---

do shell script "hwprefs cpu_nap=true"

---

I've got two applescripts "Silence" and "Squeal" that I launch from quicksilver before I play WoW (or any other activity that pushes a lot of graphics data across the bus)

Thanks Nugget I'll give that a try. I'll look into the GeForce card you have. I'm running the 23" ACD. I ran several renders in Lightwave and did some Photoshop work and no chirps. Going to hit WoW again.

J...

Yes. For me it was an easy fix. Every time i did anything graphic like resize a window
which heats up the GPU on your video card fast the fan in the front of that air flow section
would spin up and then Chirp Chirp Chirp. Thing is since most everything i do and a lot
of what OSX does, pushes the video card so i had a lot of chirping.

So i call Applecare and tell them I want it fixed and the person is like well chirping noise
is not exactly something we cover. some people just are overly sensitive to certain sounds.
I laugh and say "Oh really well how about I hold the phone in front of my G5 and you
listen and tell me if you think nothing is wrong"

So i hold the phone right in front of the fan grill area that is chirping like crazy and the
Applecare person says "Oh my! that is horrible! Ok that is not normal you should take it in
to get fixed and it will be covered under applecare" I say I know exactly what the
problem is and it is a user replaceable part. I just need you to send me that part.

So she does and overnights it even for free. I get the new fan and it takes just minutes to
swap out and that is the end of the chirping and has not returned and that was months
and months ago.

Turned out to be the fan bearings were packed too tight and it is a problem with
many of the fans Apple used from the company that makes them for Apple.

Good luck in getting yours fixed

My Rev B dual 2.0 made a high pitch whine when transferring stuff over FTP on the home network but upgrading to Tiger fixed that. Go figure.

I'm glad your issue turned out to be simple to fix. The "chirping" noise that many of us experience (which can be silenced in software with NAP mode) is not so simple, though. It's definitely not a fan bearing making the noise, and it's not related (that I can tell, at least) to any moving part. It seems to be some weird sort of interference caused whenever high volumes of data are being shuffled around inside the machine.

My TiBook made a similar noise, also during periods of intensive video activity.

We must be talking about two types of noise here, as I'm sure mine is mechanical, more like what Groovy described. I also called Apple care and had them listen to it, and they said to bring my G5 into a service center.. not! Which fan exactly did they replace for you Groovy? The two removable ones that sit infront of the PCI cards?

I tried to do the scripts you suggested and they wouldn't run. Then I realized I didn't have CHUD installed so I grabbed that and the scripts ran fine. By fine I mean they executed without errors. I had:

[Silence Script, as an app]
do shell script "hwprefs cpu_nap=true"

[Squeal Script, as an app]
do shell script "hwprefs cpu_nap=false"

I ran Silence and still had the chirp. Then I thought about those lines and thought they should be reversed. So I changed the scripts to this:

[Silence Script, as an app]
do shell script "hwprefs cpu_nap=false"

[Squeal Script, as an app]
do shell script "hwprefs cpu_nap=true"

Re-ran WoW and the chirps are gone. Like I said I'm new to this but thought I would post in case anyone else is/wants to try this as a solution.

Thanks again.

J.

I had them send me a new fan and it was easy to swap out myself.
It was the front fan with the internal speaker connected to it that sits in the
PCI/AGP section and is about 1 inch from the front grill. It is just one fan not two.


this fan (page 7 has a great pic of it)

http://manuals.info.apple.com/en/PM...ker:Fan_DIY.pdf

Well i used to think that also but putting your mac in nap mode may throttle the CPU
or other components just enough so that not as much heat is made and thus no chirping
from slower running fan. The thing is when i say chirping i truly mean chirping as if a
tiny bird was chirping. (I wish i saved the the sound recording i made of it)

What are the odds that 2 different things, one mechanical and one not, make
the exact same sound that can only be described as chirping? Is your sound a
sound that chirping best describes it or not? (my sound sure was)
A recording posted here would be nice and I could tell you at least if it was what i heard.

BTW - Why haven't you located the exact sound source? You should have no problem
finding exactly where the sound is coming from be it power supply, fan, or
whatever. (at the very least which air flow section it is coming from)




And what you say above means more heat via higher CPU loads and other components
to move all that data and the TiBook same thing, as well as higher GPU load. The fans
could very well be running faster.


Anyway, I hope you figure it out and get it fixed so everyone else can too.

It is not a fan. I don't know how to say it any more plainly.