[hpence]

Funny I stumble accross t his thread when i did... I can contribute to both the topic and the hijacking

I am also a Austin local. Born and raised around the south and west outskirts, always within a 30 min drive of downtown. I'm now attending UT where i live just north of campus along 27th street. Austin life rules - especially when your virtually on campus 24/7. I just wish i wasnt working full time this summer and could enjoy the college activites a bit more.... aw hell yea.

on topic: I am currently in possession of the dual 2.5ghz G5 that has this very same chirping issue. I'm 100% sure it is not a fan or mechanical in any way. It is the most audable when adjusting the system volume via the keyboard and sometimes when scrolling through the dock. Happens on window sizing/moving... but not quite as often as others describe. Its just loud enough to notice over soft noise, but if music or a game is playing it would be totally drowned out.

Whats struck me as odd - is it gets considerably louder when i have USB speakers plugged into one of the rear USB ports. This makes me think its something to do with the 12v load. I cant put my finger on the exact source... but it does not sound like its coming from the power supply - more like the memory area (but then again, who know how sound would dampen, echo or resonate inside that case).

I haven't tried the nap fix, but am willing to give it a shot. I'll also try different USB configs to see how that affects it. (the speakers were the original cube USB speakers - so they drew a considerable amount of power off the 12v USB line).

[Aevron]

I just recently brought my Dual G5 2GHz PM into the Apple Store to be serviced for this very reason. They replaced the power supply but the issue is still there, although it seems to be a little better.

I was told that the new power supply would reduce the power supply acoustics but it will still be audible in a very quiest room. I was also told that setting the processor performance to highest would lessen the noise a little more, but that doesn't seem to affect anything.

I can live with the issue, but I just wish they would have a fix for this. It doesn't seem to be an issolated issue because I checked the display PMs in the Apple Store and they also have this problem.

[Xtraz]

The DVI port / cabling may be part of the cause. I find that when my machine starts chirping, I can wiggle my DVI cable a little and find a position that minimizes the noise.

Can someone else try this and see if this is the case for other people also?

[Nugget]

Wiggling the DVI connector has no effect. I also tried unplugging all my USB and FireWire devices, which also had no effect.

[hpence]

sorry i didnt post back sooner.

I tried the USB speakers in different ports on the machine and it did seem to affect the sound somewhat. I tried them in the back ports, front ports, and via the built in UBS hub in an aluminum display.
All sounds seemed to be slightly different, but it was hard to pin down since there is only so much my ears can make out of a high pitched eletric wine. Either way - This makes me think more and more that the problem is power related - 12v power to be exact.

I haven't tried the DVI wiggle, but will soon and i'll report back.

edit: forgot to report that both machines were running os 10.3.8 - though I dont think that would play much of a role in my current theory.

[Briareus]

My G5 (Refurb rev.A dual 2Ghz, 2.5GB RAM, OSX 10.4.1) only exhibits the squeakies when doing CoreImage stuff (such as QuartzComposer and the Adjust sliders in iPhoto). Processor performance is set to Automatic, and I don't have CHUD installed and haven't changed the nap setting. Since it's only evident in these circumstances it's not a big issue for me.

I remember hearing it more often on my Mac when I was running 10.3.x.

[Todd Madson]

I finally was able to make my machine do it and here's the crux of it:
-The app must utilize the graphics card heavily.
-Other apps that are CPU heavy but not graphics heavy doesn't do this.

I did a little experiment using X-Plane since that is my game of choice I suppose.
At default settings, there was no problem. But for fun, I set everything to maximum
and the famous sound happens.

-What I am hearing sounds like a very high frequency oscillation, almost like a
piezoelectric buzzer set to a very high frequency of pitch.

-I would love to figure out the folks who are experiencing this:
-What is your machine (dual 2.0, dual 2.3, dual 2.5, dual 2.7?)
-What is your graphics card?
-What apps do you have that cause this (i.e. graphically intensive).
-What monitor are you using (digital flat panel?) and what resolution are you driving it at?

Thoughts:
-When I use the machine as I normally would (music apps, composition/sequencing,
iTunes, Safari, Camino, Firefox, Terminal, Seti at Home, etc.) usual things - it doesn't do this.

-I will try and do some more games with very high settings and/or graphics demos to see
if I can stimulate it to occur or not.

My findings so far:
It ONLY does it when I stress the graphics card. I crank the speakers a little higher and
it doesn't bother me at all. But it is annoying.

What's next?
I'm going to go to XLR8yourmac.com tonight to run some of the graphics card benchmarks.
I'm going to see if I can't find a methodology to the problem.

Interestingly: my Radeon 9600 XT does not appears to have a fan, just a heatsink.

One more bit that might interest you: how many of you have pets like cats? Cats have
extremely excellent high frequency hearing capabilities and my cat has a "cat cup" he
normally naps in next to the computer.

Since I have gotten the G5, he's stayed away (yes, it's larger but there has to be some
other reason he doesn't like hanging around it since it's about four to six times quieter
than the G4 was). I even plopped him into his little cat cup when the G5 was running
once to see what he would do and he walked about four feet away then laid down on top
of a paper grocery bag. Interesting. Anyone else have pets not liking what they hear
when around the G5? And this is during normal operation, not the X-Plane stress-fest.

[hpence]

to sum up my experianes:

dual 2.5ghz G5 with a 6800ultra and 3.5gb of unnammed memory -
no beeps/chirps ever noticed.

dual 2.5ghz with a flashed radeon 9800pro and 2.5gb of samsung memory -
beeps ALWAYS when scrolling through the dock (maginication is enabled, but that does not use any sort of shaders - aka core image)
Beeps frequently, though inconsistantly when playing World of warcraft (all shaders enabled).
Beeps sometimes when just sitting idle on desktop, nothing but itunes/safari running.
Beeps seem to change tone/frequency when USB speakers are moved to different ports (usb speakers have a relatively heavy load on the 12v power)

Both systems were running 10.3.8

I have the 2.5ghz with 9800pro in my possession and a 9600XT they oringally shipped with. I can swap the graphics cards in the near future to see if that changes anything.

[Lucky8]

Originally Posted by hpence

I have the 2.5ghz with 9800pro in my possession and a 9600XT they oringally shipped with. I can swap the graphics cards in the near future to see if that changes anything.

When you say 9800pro, do you mean 256MB 9800pro SE?
Are they better than 9600XT?

[bells0]

Dual 1.8, rev B, 9600XT 128mb, 2gig Ram, 2 x 160 sata - running a tft through dvi...............[on tiger, but did in panther too]

[Markarian421]

Originally Posted by Skypat

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

I just got the same machine, and I'm glad to hear I'm not the only one with this. It's a low humming tone with about a 3 second cycle (peak to silence). Maybe it's a harmonic between a couple fans spinning at almost but not quite the same speed.

[hpence]

Originally Posted by Lucky8

When you say 9800pro, do you mean 256MB 9800pro SE?
Are they better than 9600XT?

Its a basic, retail 9800 pro, 128mb. (its actually a sapphire card i flashed over from the PC side, but its 100% identical to the mac retail version 'cept for the sapphire sticker)

The 9800 pro is a good deal faster than a 9600XT. It has 8 pixel rendering pipelines rather than 4, and a 256bit memory interface rather than 128bit. If i had to slap a number on it... id say between 30 and 40% faster when both are at stock speeds.
Downside to the 9800pro is it doesnt have an ADC port, but it does have s-video for tv-out.


I haven't yet swapped back to the 9600xt to see if the chirps change... but it is still on my to-do list.

[David Thompson]

Originally Posted by hpence

The 9800 pro is a good deal faster than a 9600XT. It has 8 pixel rendering pipelines rather than 4, and a 256bit memory interface rather than 128bit. If i had to slap a number on it... id say between 30 and 40% faster when both are at stock speeds.

In my G5 dp2.0 running xbench I get:

9650XT

Quartz Graphics Test 245.13
Line 223.83 5.70 Klines/sec [50% alpha]
Rectangle 215.16 15.14 Krects/sec [50% alpha]
Circle 232.69 5.36 Kcircles/sec [50% alpha]
Bezier 240.08 2.61 Kbeziers/sec [50% alpha]
Text 354.70 5.78 Kchars/sec
OpenGL Graphics Test 221.64
Spinning Squares 221.64 155.10 frames/sec
User Interface Test 379.86
Elements 379.86 122.18 refresh/sec

9800Pro

Quartz Graphics Test 246.93
Line 227.05 5.78 Klines/sec [50% alpha]
Rectangle 215.06 15.13 Krects/sec [50% alpha]
Circle 232.53 5.36 Kcircles/sec [50% alpha]
Bezier 241.26 2.62 Kbeziers/sec [50% alpha]
Text 363.78 5.93 Kchars/sec
OpenGL Graphics Test 228.41
Spinning Squares 228.41 159.84 frames/sec
User Interface Test 387.97
Elements 387.97 124.79 refresh/sec

So, not really any appreciable improvement that I can see...

[SlideWRX]

So there's the heart beat (heart Beep?) noise that CHUD NAP preferences apparently cancels (I'll try that this weekend), and then there's the chirping from video-intensive applications, that I get when playing wow. refurbished Dual 2GHz here, just bought. Apparently some machines also have noisy fans for the power supply in addition to this.

Yes, the machine is tremendously quiet, which brings that much more attention to the little transient noises.

Anyway, I haven't found instructions to remove the dual heatsinks to get at the power supply - most of the instructions show a single heatsink witha different attachement scheme. Any help?

Tom

[d.fine]

Originally Posted by David Thompson

In my G5 dp2.0 running xbench I get:

9650XT vs 9800Pro ... So, not really any appreciable improvement that I can see...

That's not a big difference. But you put 9650XT, or do you mean 9600XT ? The 9600 is faster than the 9650, so if you mean 9650 then the 9600 could be faster than the 9800...

[David Thompson]

Originally Posted by d.fine

That's not a big difference. But you put 9650XT, or do you mean 9600XT ? The 9600 is faster than the 9650, so if you mean 9650 then the 9600 could be faster than the 9800...

Well, I ordered the 9650. One of the receipts Apple sent me said:

Item Product Product Description Total Total Unit Extended
Number Ordered Shipped Price Price
002 Z0BK PMG5 CTO 2.0 DP 1 1 2,124.00 2,124.00
SerialNo.: ( xxxxxxxxxxxx)

The unit above contains the following options:

Processor 065-5745 Dual 2.0GHz PowerPC G5
Memory 065-5540 512 MB DDR400 (PC3200)-2X256
Hard Drive 065-5536 250GB Serial ATA-7200rpm
Optical Drive 065-5537 16x SD DL(DVD-R/CD-RW)
Graphic Support 065-5539 ATI Radeon 9650 XT w/256MB

The system profiler says:

ATI Radeon 9600:

Chipset Model: ATY,RV351
Type: Display
Bus: AGP
Slot: SLOT-1
VRAM (Total): 256 MB
Vendor: ATI (0x1002)
Device ID: 0x4150
Revision ID: 0x0000
ROM Revision: 113-A58503-115

So, I'm not entirely sure what graphic card I've got...

[rhogue islander]

I have a rev A Dual 2.0 G5 and have always had the chirping issue, along with a 'raygun' sound effect when performing network transfers of large files. Its always been infrequent enough and low enough in volume (tower on floor) that it hasn't really bothered me much. (I just assumed the gerbil wheel inside the machine needed a squirt or two of oil )

After my upgrade to OS 10.4 the noises increased in frequency and volume to the point where it was becoming irritating. I read either here or over at xlr8yourmac that trashing all of your power preferences and rebooting would return your machine to normal, which it did.

So I live with it and it doesn't bother me, but it certainly strikes me as odd. I have built quite a few PC's and used several different manufacturers' quality power supplies and have never heard anything remotely like it from any of them.

[booboo]

Originally Posted by Markarian421

I just got the same machine, and I'm glad to hear I'm not the only one with this. It's a low humming tone with about a 3 second cycle (peak to silence). Maybe it's a harmonic between a couple fans spinning at almost but not quite the same speed.

I'm glad you mention this, I'm pretty sure it's the top two fans at 90 degrees to each other in the top section of the G5 case. So easy and cheap for Apple to fix. You'd have thought they learned their lesson from the most annoying twin-fan combo ever in the MDD's.

Just stop one of the fans with your finger (if you dare) to hear how much less annoying a consistent - rather than semi-random cyclic - noise is. I The answer is to replace one of the fans with another that runs at different speed once your warranty expires.

I mentioned it in this thread (shameless plug)

The chirping noise, IMO, is present in 98% of G5 PowerMac's. If your Mac is in an office or somewhere else where there is never true quiet, you may never notice it.

Musicians in particular are aware of the noises (and other audio-related issues) with the G5. Do a search for 'chirp' in a Mac-audio forum to see the true extent of the problem.

It was much, much worse in Rev A machines. It's nothing to do with what other hardware you have installed or connected, or what software you're running, although all of these things may influence whether a chirp is produced.

The best explanation I've heard is that capacitors in the PSU are acting like tweeters. This happens when the current draw is being cycled between on and off at a high frequency, which is why disabling NAP cures it.

There is the possibility that covering the offending caps in gloop (which was always the traditional preventative measure) will fix it.

There is a fabulous little app that can even play a tune on your G5 PSU if it is afflicted.

In its own little way, it's one the most fantastic app's ever.

Check it out, Bo Selecta!

[Todd Madson]

I'm really bummed, I was hoping my power supply would play a scale. Sadness.

Can anyone record an MP3 of this?

I believe a reason mine does not do this is because this machine was once a
Dual 2.5 display unit for Microcenter. Would be bad for potential customers...

[booboo]

If no-one beats me to it, I'll post one in the next couple of days . . .

[turk.o]

booboo, that app is awesome, my G5 plays a mini-symphony, finally something useful out of the dreadful noise. well, maybe not useful, but still . . .

anyway, my 2¢--i've had a rev. a 2x2Ghz powermac for almost two years now, and after three trips to the apple service center getting new powersupplies and motherboards i gave up, realizing apple would never fix the problem. i had the chirps and noise to a high degree. against advice i downloaded the CHUD tools and de-selected nap and it completely removed the noise. i haven't switched it back on in those two years and have had no problem on my computer to speak of. mileage may vary. i certainly won't buy another power mac if they can't fix this simple issue. it is a brazenly dumb idea: make a super quiet computer so you can hear annoyingly high pitch tones that irritate forever. maybe they should put some ipod engineers on the problem or somehting?

[mpancha]

Originally Posted by jamil5454

Nugget, I don't mean to hijack the thread, but where in Austin do you live? I just moved here for school, down by Riverside Drive and Congress. On Thursday I've got a job interview at the Barton Creek Apple Store, and they're looking to hire about 10 people. If I get it that would Rawk.

But who cares?

Originally Posted by Nugget

I'm in northwest Austin, up by 183 and Anderson Mill Road. "South Dallas" if you ask folks from south of the river.

No way... I'm in S. Austin, off mopac/Ben White.

Good luck with the apple store interview jamil.

[Markarian421]

Originally Posted by Todd Madson

-I would love to figure out the folks who are experiencing this:

I got my dual 2.3 Ghz w/Radeon 9600 128 MB maybe 2 weeks ago now. I noticed this occasionally but only rarely and briefly until I switched monitors a few days ago, from an old 1600x1200 vga CRT to a 1920x1200 DVI flat panel. Now the machine has prolonged bouts of chirpiness.

Just now I could reproduce it with the RSS news feed screen saver in preview mode. Some news feeds make it chirp, others don't, I'm not sure why -- maybe total size of the text rendered? I also notice if it's on a feed where it's chirping a lot the animation seems to stutter a bit.

I've had a lot of PCs and the noise doesn't seem like an unusual one to me (it just now occurred to me that "oh yeah, this is what they were talking about") but it's easier to hear with the PowerMac because otherwise it's some much more quiet than the average PC I've had.

Originally Posted by Todd Madson

One more bit that might interest you: how many of you have pets like cats?

My cats still spend all day in the same room as the PowerMac if I'm in here.

[Markarian421]

Originally Posted by booboo

Just stop one of the fans with your finger (if you dare) to hear how much less annoying a consistent - rather than semi-random cyclic - noise is. I The answer is to replace one of the fans with another that runs at different speed once your warranty expires.

Even a small resistor inline might do it too, I'll have to see how easy that would be. Actually since I moved mine under the desk I can't hear it as much any more.

Originally Posted by booboo

There is a fabulous little app that can even play a tune on your G5 PSU if it is afflicted.

Hmm, I've got a chirpy mac but no scale for me.

[hpence]

Originally Posted by David Thompson

In my G5 dp2.0 running xbench I get:

9650XT
...
9800Pro
...(removed for space)

So, not really any appreciable improvement that I can see...

The problem is that your running Xbench. Xbench is t he absolute worst when it comes to measuring graphics capability. Throw in a game thats reasonably optimized for mac (quake3, halo, WoW, doom3) and you will see a huge difference between the 9800pro and any 9600

also - no such thing as a 9650XT. the 9650 is running at pro speeds, so it is actually slower than the 9600XT.

[hpence]

Originally Posted by booboo

The best explanation I've heard is that capacitors in the PSU are acting like tweeters. This happens when the current draw is being cycled between on and off at a high frequency, which is why disabling NAP cures it.

There is the possibility that covering the offending caps in gloop (which was always the traditional preventative measure) will fix it.

There is a fabulous little app that can even play a tune on your G5 PSU if it is afflicted.

In its own little way, it's one the most fantastic app's ever.

Check it out, Bo Selecta!

First I her about the leaky caps in the iMacs, now singing caps in G5s... awesome. Seems apple needs to find a higher quality source of capacitors all together.

Anything think gooing, or bracing the offending caps with rubberbands will void the warranty?

[OogaBooga]

Originally Posted by Markarian421

Even a small resistor inline might do it too, I'll have to see how easy that would be. Actually since I moved mine under the desk I can't hear it as much any more.



Hmm, I've got a chirpy mac but no scale for me.

Try putting your ear up to the grill. At first I thought I couldn't hear it, but then I realized I was hearing a faint electronic scale. Once I disabled NAP, it immediately stopped. So the chirping and the scale program are definitely related.

[hpence]

I just tried out that systemload app to play the scale. Thats freakin hilarious!! It plays the scale somewhat quieter than the normal chirping, but i can definitely hear it when i put my ear to the grill.

[Markarian421]

Originally Posted by OogaBooga

Try putting your ear up to the grill.

Ah ok I hear it now, but only a few notes with pauses in between. And yes much more quiet than the chirping.

[Sparkletron]

Originally Posted by jamil5454

It can barely be described as chirping, but it's more like very high pitched fast pulses/whine that occurs whenever a lot of data is moving across the graphics bus. It kinda sounds similar to that high pitched whine emitted by a TV when you first turn it on.

Some people may not be able to hear because the frequency is too high, but for those that can hear it it gets really annoying, really fast.

It's definitely more of an electronic sound, not mechanical.

I've heard this sort of sound in many electronic devices. My guess is that it's a faulty LC circuit in the power supply. A faulty inductor. If you could get access to the power supply, you could find the exact inductor responsible and put your gloved finger on it and the sound would stop--until you removed your finger.

-S

[- - e r i k - -]

Hey, what happened here?

Code:
Rocky:~ e**d$ hwprefs cpu_nap=false
-bash: hwprefs: command not found

[mhuie]

My brand new DP 2.0 (latest rev) w/ the 9600 128mb. I'm running at 1600x1200. The only time I hear a slight chirping playing WoW, and that was it when my other PC is off and my speakers are turned off.

Pretty much a non-issue for me.

[svtcontour]

To me it just sounds like a leaky cap in a powersupply - unless the noise I'm sometimes hearing the the dual 2.0 at work is in fact what i just described.

[Madrag]

Originally Posted by - - e r i k - -

Hey, what happened here?

Code:
Rocky:~ e**d$ hwprefs cpu_nap=false
-bash: hwprefs: command not found

you need to install CHUD tools.

About the chirps, I also have them and have used the Nap method to remove it (I used the applescript advice and created an app and use it in the startup items of my users).

Now, why it's not advised? is it because it reduces the processor's life?

I'll also will try something that hasn't been done (or metioned), which is to disconect the screen from the PM and see if the chirps happen or not... (I'll use another mac connected via VNC, so that I can click and test).
If it doens't chirp, then it really has something to do with the video...

[danman]

Dual 2.0, X850XT, 4GB RAM, it chirps all the time. Ran the Nap=false command and all is quiet now.

Now what does NAP actually do? I don't think anyone in this thread has answered it yet?

[Madrag]

I think it has been covered:

Originally Posted by jamil5454

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.

[danman]

How do I get it to be disabled when ever I reboot?

[Lucky8]

Originally Posted by danman

How do I get it to be disabled when ever I reboot?

Sorry, but how do I disable it?
What is CHUD tools?
What is VNC?

[danman]

Download CHUD here - http://developer.apple.com/tools/download/

And then run the command below from a Terminal window:

hwprefs cpu_nap=false

[Lucky8]

Originally Posted by danman

Download CHUD here - http://developer.apple.com/tools/download/

And then run the command below from a Terminal window:

hwprefs cpu_nap=false

Is this going to shorten the life of my processors?

[danman]

From what I understand, No, not at all. Overclocking your processors will reduce the life, but your not overclocking.

[OogaBooga]

If you actually put your ear up to the lower back part of the machine, you can hear the noises the best. This is where the PSU is.

[danman]

So how do I make it run the NAP fix at startup? Please forgive me, I'm a native windows user. If you told me how to run a command at startup each time on a windows box I'd know, but a Mac I'm, at a loss.

[Madrag]

Originally Posted by danman

So how do I make it run the NAP fix at startup? Please forgive me, I'm a native windows user. If you told me how to run a command at startup each time on a windows box I'd know, but a Mac I'm, at a loss.

ok, here goes:

1. open applescript (applications/applescript/Script Editor.app)

2. paste this code:
do shell script "hwprefs cpu_nap=false"

3. Now save it as an application, with a name (ex: disable_nap.app)

4. place it in a permanent place (like the applications folder)

5. go to the system prefs and inside the users prefs, go to the startup items; add (press the +) and select the recently created applescript.

that's it. Each time you reboot/login, the nap will be disabled

There may be other methods but this is quick.


About VNC, do a search please.

[danman]

Perfect, Thanks!

[mcavotta]

I've read this entire thread in an effort to ID the faint, metronome-like beep/chirp emanating from my new G5 Dual 2.7. However, the noise I hear is only audible in a silent room and is always present. This seems different than the load-induced noises many describe here. Or am I mistaken? My bird chirps every second or so, like a heartbeat. FWIW, I tried the no NAP fix with CHUD and it didn't do anything for me.

Help for a 2-week old Switcher?

-M

[mcavotta]

test

[Madrag]

Some people have reported both the "metronome" chirp and the Video induced one...
Now, if disabling NAP isn't working for you, then maybe you have a diferent problem...

[tribalogical]

I've tried the script, but it tells me "hwprefs: PERMISSION DENIED: effective user id MUST be root user to run"...

why am I the only user here running into this? (just my luck!)

I'm running Tiger 1.4.2, CHUD Tools v 4.2.2... dual 2.7Ghz G5...

My system has a primary admin account (for audio production, etc.), and a second user account (for games, and so on).

I tried prefixing the sudo command but that doesn't work either. Help is much appreciated! (Currently I'm disabling Nap manually after every reboot via the "Processor" system pref....)

Thanks in advance...

peace,
tribalogical

[OogaBooga]

Originally Posted by mcavotta

I've read this entire thread in an effort to ID the faint, metronome-like beep/chirp emanating from my new G5 Dual 2.7. However, the noise I hear is only audible in a silent room and is always present. This seems different than the load-induced noises many describe here. Or am I mistaken? My bird chirps every second or so, like a heartbeat. FWIW, I tried the no NAP fix with CHUD and it didn't do anything for me.

Help for a 2-week old Switcher?

-M

I actually here this from my Rev. C 2.0 too, but it's very faint. It's a quiet beep that occurs every second. I can only hear it when I put my ear up to the PSU. It sounds like a little mechanical clock inside my machine.