Audio Decoding KILLS MacPro (2009) green factor

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
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Pacific NW, USA
Audio Decoding on the 2009 Mac Pro causes the CPU temps to hit near 100% load temperatures and voltage requirements... Yielding a 30(c) rise in temps and a 50w additional power just for the task of Audio playback. Is this an OS X issue or hardware? This issue appears to invalidate major marketing points of the platform.

Its frustrating seeing a MP3 file played in Quicktime, bring the CPU voltage and temps so high.... This Can't be good... Ripping a DVD and listening to music pushes the Core i7 CPU to near 80(c) temps!! Basically bug turns the Mac Pro into a Heat Miser..

In this POST, VIRTUALRAIN took the time to document the severity of the long debated issue with detailed charts and data.

This issue has garnered the time and attention of many MR users and everyone attention to get to the bottom of this apparently Serious issue is greatly appreciated.



(updated)
 

MacApple21

macrumors member
Mar 12, 2009
93
0
Denmark
Audio Decoding on the 2009 Mac Pro cause the CPU temps to hit near 100% load temperatures and voltage requirements... Is this an OS X issue or hardware?

Its frustrating seeing a MP3 file played in Quicktime, bring the CPU voltage and temps so high.... Can't be good...
It sounds strange, even my old MacBook can play music files without raising the temperatures too much, it will surely increase the fan speeds a bit, but it won't increase the CPU temperatures or workload that much :eek:
I would contact Apple.
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
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Pacific NW, USA
Is anyone else with a 2009 MacPro seeing this issue? There was a thread where people were saying their box was running hot.. They thought it was iTunes...

It turns out that any kind of audio decoding causes the increase in heat / Voltage usage. It's not just the built in audio hardware as it happens with that OR a USB based audio system.

Idle: 31(c)

Play Audio for 3 Mins 60(c) - 1% CPU utilization

or

Max all CPU's for 3 Mins 65(c) - 800% CPU Utilization


The temp readings are taken from iStat menus or smcFanControl.
 

thehimay

macrumors member
Mar 17, 2009
54
1
Toronto, ON, CA
Extra info would be nice, especially in regards to any controls you maybe did? Just seems like too arbitrary of an evaluation the way you presented it.

Was that 1% utilization an average, peak or minimum value? Did you try any non-decoding sources of utilization to match that and see how those worked? What was the background utilization?

At 800% utilization, have the fans increased in speed at all? What were you maxing out the CPU load with?

I haven't seen any of this discussion about the 2009's running hot, so if this information is already over there in some form or another, just send me that way.

EDIT: Just browsed through the thread about '09's running hot. Where'd you find information that it was audio decoding in general vs. just iTunes?

Has anyone tried running iTunes in minimized mode vs. full window to see if that makes a difference?
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
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Pacific NW, USA
Extra info would be nice, especially in regards to any controls you maybe did? Just seems like too arbitrary of an evaluation the way you presented it.

Was that 1% utilization an average, peak or minimum value? Did you try any non-decoding sources of utilization to match that and see how those worked? What was the background utilization?

At 800% utilization, have the fans increased in speed at all? What were you maxing out the CPU load with?

I haven't seen any of this discussion about the 2009's running hot, so if this information is already over there in some form or another, just send me that way.

EDIT: Just browsed through the thread about '09's running hot. Where'd you find information that it was audio decoding in general vs. just iTunes?

Has anyone tried running iTunes in minimized mode vs. full window to see if that makes a difference?

I have a "CLEAN" Snow Leopard partition that isolates any software conflicts. Processor usage was about 1% give or take. Nothing real going on. The fans did not increase when playing audio. When maxing CPU, BOOSTA kicked up to 1200 when CPU hit 65(c) then back down to 1050.

The heat issue showed up with each of the following. No differences.
  • The issue showed up with iTunes as advertised - Internet radio stream and ACC file. CPU cooled/voltage drop when audio stopped. Visualizer caused no difference in temps.
  • Played a MP3 file with Quicktime. CPU cooled/voltage drop when audio stopped.
  • Played a MP3 file with VLC. CPU cooled/voltage drop when audio stopped.

When I run into issues... I generally like to isolate it to the lowest common issue - in this case it is audio decoding / playback.

I know CPUS are made to cook.... But this is excessive....
 

CubeHacker

macrumors 65816
Apr 22, 2003
1,082
11
Decoding of an mp3 file takes approx 60mhz of speed - or about the speed of the first released Pentium chip. Considering you have several cores, each running at 2000+mhz, there is no way in the world listening to an mp3 would use up all your CPU cycles unless there is something strange going on.
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
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That's why i think something is going wrong here...

IF we could get some more 2009 owners to chime in... It would help provide a sampling of different systems.

I have a gut feeling that this isn't an isolated issue. Any CPU that peaks near temps of 100% load when playing audio on a 1% load... Means something is definitely wrong...

Could this be a symptom is Software Based audio decoding in the CPU?
 

CubeHacker

macrumors 65816
Apr 22, 2003
1,082
11
Could this be a symptom is Software Based audio decoding in the CPU?
All mp3 audio decoding is done in software AFAIK. Sure, the sound is played through the audio hardware, but the physical decoding of the mp3 steam is done by the CPU. However as i said before, it takes very very little power to do that on a computer from 2009.

To run a valid test, you would need to provide us with a link to an mp3 thats causing this problem, state exactly what program you use to listen to the mp3, and your exact stats shown through activity monitor - a screenshot would help.
 

Cynicalone

macrumors 68040
Jul 9, 2008
3,209
0
Okie land
I have always thought it was a problem with iTunes. I see a 15 to 20 degree temperature increase when using iTunes to listen to music.

2009 Mac Pro
2.93 Octo Core
32GB of RAM
iTunes 9.0.1
OS X 10.6.1

In the time it took to type this it went from 49º Celsius to 60º Celsius listening to music with iTunes.
 

jjahshik32

macrumors 603
Sep 4, 2006
5,259
1
Audio Decoding on the 2009 Mac Pro cause the CPU temps to hit near 100% load temperatures and voltage requirements... Is this an OS X issue or hardware?

Its frustrating seeing a MP3 file played in Quicktime, bring the CPU voltage and temps so high.... Can't be good...
Is the problem from the 3.3GHz QUAD Mac Pro? If so, could it be due to you customizing it?
 

AZREOSpecialist

macrumors 68020
Mar 15, 2009
2,103
880
Audio Decoding on the 2009 Mac Pro cause the CPU temps to hit near 100% load temperatures and voltage requirements... Is this an OS X issue or hardware?

Its frustrating seeing a MP3 file played in Quicktime, bring the CPU voltage and temps so high.... Can't be good...
The major difference with your system is that you replaced your stock CPU with a Core i7 975 Extreme. While this may not be the cause of your issues, it is sufficiently different from most Mac Pro systems. After playing two songs in iTunes while simultaneously running the classic visualizer and enabling the equalizer, my CPU temps hover around 57C. I am running on a Xeon W3580 @ 3.3 GHz.

Do you have the original Xeon that shipped with your Mac Pro? If so, I would suggest swapping it back in and see how things go. Also, when you put in the Core i7 975, did you apply your thermal paste as indicated here (see lower right corner for Core i7)? It needs to be applied in line with the core placement.
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,688
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Pacific NW, USA
All mp3 audio decoding is done in software AFAIK. Sure, the sound is played through the audio hardware, but the physical decoding of the mp3 steam is done by the CPU. However as i said before, it takes very very little power to do that on a computer from 2009.

To run a valid test, you would need to provide us with a link to an mp3 thats causing this problem, state exactly what program you use to listen to the mp3, and your exact stats shown through activity monitor - a screenshot would help.
This happens with any MP3, ACC, or even streaming audio...

Is the problem from the 3.3GHz QUAD Mac Pro? If so, could it be due to you customizing it?
I don't think it's from the customization as Cynicalone as the 2.93 and is seeing the same issue.


That would be my first guess. I would suggest calling Apple after you have tried to put the original CPU back in if it is a further issue.
Hey Techie... What temps are you seeing?


I have always thought it was a problem with iTunes. I see a 15 to 20 degree temperature increase when using iTunes to listen to music.

2009 Mac Pro
2.93 Octo Core
32GB of RAM
iTunes 9.0.1
OS X 10.6.1

In the time it took to type this it went from 49º Celsius to 60º Celsius listening to music with iTunes.
A 15-20 degree jump in temp, along with the increase in voltage makes no sense for playing music... When typing this I just saw my system go from 29 to 53 and its still climbing. This is with Quicktime player and with no visualizer to throw it off. Also playing out through the built-in speaker.
 

jjahshik32

macrumors 603
Sep 4, 2006
5,259
1
Hmm.. Mines running at 55 celsius on cpu A and 46 celsius on cpu B, I do have itunes running in its own space using spaces but then I'm constantly running 16 spaces with many apps + vmware fusion for windows vista...

But I do notice that itunes is a resource hog.
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
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Pacific NW, USA
Hmm.. Mines running at 55 celsius on cpu A and 46 celsius on cpu B, I do have itunes running in its own space using spaces but then I'm constantly running 16 spaces with many apps + vmware fusion for windows vista...

But I do notice that itunes is a resource hog.
The funny thing is.. Quicktime was completely rewritten for SL and the same effect happens with it.

Don't they always say running a CPU at high heat over a period of time shortens its life?
 

nanofrog

macrumors G4
May 6, 2008
11,718
2
The funny thing is.. Quicktime was completely rewritten for SL and the same effect happens with it.
Which can means the odds for bugs (even CPU specific) are higher, and the most likely potential cause, if it's happening on multiple systems.

Don't they always say running a CPU at high heat over a period of time shortens its life?
Yes, but it's referring to temps hitting or exceeding the design limits of the CPU/s.

So long as you stay under the rated max Temp (listed at 100C for yours = "meltdown"), you should be OK. Greater differences from the max though are always a good idea. :)

BTW, load at stock clocks should be ~67C @25C ambient.
 

AZREOSpecialist

macrumors 68020
Mar 15, 2009
2,103
880
There's also a lot more headroom on the W5500 series used in the 8-core. All W5500 series used by Apple have 95W TDP and 2/2/3/3 turbo boost speed bins vs. 130W TDP and 1/1/1/2 turbo boost speed bins on the W3500 series used in the Quads. This means the 8-cores will have lower temps and higher turbo boost speeds than the Quad, which will run hotter.

The W5580 and W5590 are the two exceptions with 130W TDP. I can't find any information on the speed bins available for turbo boost on those steppings.
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,688
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Pacific NW, USA
I've talked to my top software/hardware engineers... the only thing we can come up with is that it's the software based APU or somethings broken somewhere.

Intel Nehalem (microarchitecture) is touted at providing 30% lower power usage for the same performance.....
 

Tesselator

macrumors 601
Jan 9, 2008
4,601
4
Japan
I've talked to my top software/hardware engineers... the only thing we can come up with is that it's the software based APU or somethings broken somewhere.

Intel Nehalem (microarchitecture) is touted at providing 30% lower power usage for the same performance.....
I'll venture an opinion and say it's Hyperthreading. Turn off HT and see how that works out. ;)