[Cadaver]

I'm finally getting tired of my G5 sounding like a General Motors wind tunnel generator (and its done this since before the infamous 10.3.8 update).

I've noticed the fan(s) speed seems to follow the temp of the memory controller heatsink (per the shareware app Hardware Monitor).

Idle temps seem to hover around 158�F (69-70�C), and the fans will rev up when this increases any... even doing mundane tasks that don't require lots of CPU time.

If you have a DP2.5GHz machine, what do your temps show? Do you also have a high-reving fan, or does my machine require a fan calibration??

I used to have a rev. A DP2.0, which was virtually always silent, so this machine is starting to annoy me somewhat. Thanks...

[MORT A POTTY]

I'll take it if you don't want it

[d.fine]

Originally posted by Cadaver:
Idle temps seem to hover around 158�F (69-70�C),

Yikes, that sounds a little too hot to me. Don't have a dual 2,5, but a dual 2,0, and idle temps come nowhere near. They typically reside around 50�C or 122�F.

What's your CPU settings under energy saver? Putting it on automatic might bring the temps down a bit, and so also the fan revs...

[Big Mac]

The DP 2.5's U3 temperature is normally a good amount higher than the DP 2.0's. It sounds like it's within the range I have read about, Cadaver. Are you on Automatic or Highest? There are several old threads with G5 temperature readings; you can also find a bunch more on g5support.com.

[Al G]

http://forums.macnn.com/showthread.p...42#post2417677

[OldCodger73]

Cadaver, right now I'm reading MacNN and litening to music on iTunes without the visualizer on. Temperature Monitor shows the memory contoller heatsink teperature as being in the 150�155 degree F range and the fans aren't reving up.

Adding iTunes visualizer to the mix and the MCH temperature moves up to the upper 150s into the lower 160s. There's an initial fan ramp up when visualizer first comes on, then from the sound of it it drops back to about what it was before.

My power supply failed last week. Before that the fans were quite active, not wind tunnel loud but still very noticable. After it came back from repair it's much quieter and the fans don't normally run louder/faster as much. Perhaps as part of the service they did a fan calibration.

In my own mind I'm not sure whether it's the MCH or the CP-A Die Temperature or perhaps a combination of both that starts the fans kicking in.

[Cadaver]

Originally posted by Al G:
http://forums.macnn.com/showthread.p...42#post2417677

No, I understand about the 10.3.8 fan issues. But, as I said in my initial post, the high U3 memory controller temps and associated fan speed is a pre-10.3.8 issue.

I'm just curious as to what other 2.5GHz owners see as their memory controller temps. Just trying to figure out if mine is running abnormally hot (in which case I'll take it in for repair) or if mine is within range, in which case I'll live with it and hope for a fix in the form of a firmware or OS update.

[Cadaver]

Originally posted by OldCodger73:
Cadaver, right now I'm reading MacNN and litening to music on iTunes without the visualizer on. Temperature Monitor shows the memory contoller heatsink teperature as being in the 150�155 degree F range and the fans aren't reving up.

Adding iTunes visualizer to the mix and the MCH temperature moves up to the upper 150s into the lower 160s. There's an initial fan ramp up when visualizer first comes on, then from the sound of it it drops back to about what it was before.

And you've got a DP2.5GHz??
Hmmm.... my temps doing essentially the same tasks float between 168-162�F.
(and I do have my system performance set to Highest)

[mainemanx]

Are any of you "hot CPU folks" running Apple's Hardware Test CD? Even without consistently high temps my B pocessor fails 1 out of 2 tests. Time to entrust it to the demons of Applecare....

[Coldwater]

Cadaver, I 'm running the same apps as OldCodger73 with the addition of FCPs viewer window with processor set on Reduced. Temps for cpus avg. 135 degrees and MCH at 164 degrees. Can hardly hear fans. When switch processor to Highest, fans speed up then back off. CPU temps stay between 157 to 165 degress with the MCH at 174 degress. Fans rarely speed up. I 've noticed that the fans are most active when set to Automatic. Also room temps have made a difference. At 65 degrees things are quiet. At 72-75 degrees more activity from fans, but not disturbing.
As I'm unable to view CPU temp monitor/MCH at the same time I'm running FCP, I can't tell which causes the fans to speed up.

I also keep the G5 on a cart,parallel to wall and pull it out a foot when in use.

If you want fan noise, my old IntelliStation M Pro 50 will blow everyones doors off. It had to be chained to the floor.

What I have observed, and it may not be correct, is that the processors what ever the setting Reduced Highest Auto, should only be creating temps within that particular range and that the fans running at their quietest rpms help to keep them there.

[OldCodger73]

Cadaver, as I follow up, yes I do have the Dual 2.5. The temperature reading I gave was with the processors set for auto. Setting them for highest the memory controller temperature is in the mid to upper 150s. This is with Safari and iTunes without the visualizer active and Word, Excel, FileMaker, and Photoshop open with no windows active. The fans perhaps do run a little less in highest. The big difference in highest is that CPU A die temperature goes from the 140s in auto to the 165-175 range.

I sure wish I could figure out a way to connect the heat from the computer to my home's heating system <grin>.

[Cadaver]

Here are my 2.5GHz G5's temps, at near-idle (several background apps sitting idle, Safari on the usual message post page w/ the animated smilies):

MCH: 158�F (70.5�C)
CPU A die: 136�F
CPU B die: 119�F

At a MCH temp above 165, at least one of the fans will rev up (quite loud) then back down after a few seconds when the temp starts to drift back down. I've seen the MCH go as high as 175�F (79�C) under full system load.

Thing is, I just don't believe the fan can cool this chip back down with in a few seconds. I'm sure the readings aren't 100% correct. And I've read that 10.3.8 was actually supposed to reduce this issue, though for me it doesn't seem to have made a difference (this machine came with 10.3.5 installed from the factory). And I did apply the 10.3.8 update via the 99MB Combo updater, too.

Edit: and for whatever its worth, my drive bay with a 300GB Maxtor and a 10,000 rpm 74GB Raptor has never gone above 80�F.

[RevEvs]

With my processor performance set to automatic, my fans keep spinning up lots and being generally very noisy.

With processor performance set on highest, they just stay at a low speed all the time and never speed up.

Basically, for quietest performance i leave my G5 on higest performance. the automatic drove me insane with the speeding up of fans!

[power142]

Cadaver: I see temperature readings similar to yours using Hardware Monitor for the memory controller, with processor dies at 75C or upwards. The fans only spin up and down for a short period every couple of minutes, while it is under almost constant load of >100% (ie at least 1 processor 100% busy). It is running 10.3.8, set to "Highest Performance" in Energy Saver.

[Cadaver]

Eh, I guess my machine is "normal." Still annoying how I can hear the fans spin up slightly when doing what should be low-load tasks like animating a bunch of GIFs on a web page. And, yeah, this is with the energy saver set to Highest. My prior rev. A DP2.0 never did this sort of thing.

Oh well... Live with it, I shall.

[osxisfun]

is the chip in the 2.5 the same as the 2.0..

or was it some early variant of the 970gx?

[MORT A POTTY]

Originally posted by osxisfun:
is the chip in the 2.5 the same as the 2.0..

or was it some early variant of the 970gx?

nope, it's a 970FX, same as the other Rev. B PowerMacs

[osxisfun]

Originally posted by MORT A POTTY:
nope, it's a 970FX, same as the other Rev. B PowerMacs

wonder what the 970GX or 907MP (if exists) do to the heat equation. i keep forgetting if they are .9 in size but then again i thought the 2.5s where .9 in size.

hopefully the next PMs will be super liquid cool or have some new fancy cooling system

[Big Mac]

Originally posted by MORT A POTTY:
nope, it's a 970FX, same as the other Rev. B PowerMacs

Not all of the Rev B. G5s use the 970FX.

[Coldwater]

Cadaver, The only difference between your temps, my home 2.5 and one I use at a clients house, is the difference of 17 degrees between the two cpu A & B . I've tried to duplicate it on both machines but can't. My temps between A & B are always 1 to 2 degrees. Could it be that the sensors are being read wrong or one processor is doing more of the work, and getting hotter faster and causing a fan to activate sooner?Just a thought.

[MORT A POTTY]

Originally posted by Big Mac:
Not all of the Rev B. G5s use the 970FX.

they are supposed to. what doesn't?

and yes, the 970FX is a 90nm part. nobody knows anything about the GX, and nobody knows if even an MP variant exists (although signs point to the affirmative)

[Al G]

Originally posted by Cadaver:
No, I understand about the 10.3.8 fan issues. But, as I said in my initial post, the high U3 memory controller temps and associated fan speed is a pre-10.3.8 issue.

I'm just curious as to what other 2.5GHz owners see as their memory controller temps. Just trying to figure out if mine is running abnormally hot (in which case I'll take it in for repair) or if mine is within range, in which case I'll live with it and hope for a fix in the form of a firmware or OS update.

My point was that 10.3.8 was supposed to FIX that particular problem. You said it doesn't in your case, so I don't know what to tell you.

I can tell you that the memory controller in rev. Bs runs quite a bit hotter than rev. As. It appears that Apple decided higher U3 temps are ok in the rev. Bs (because they use a different U3), and 10.3.8 changed the threshold for fan activity. Note, I'm talking about that single main logic board backsize fan which pre-10.3.8 was revving constantly and directly related to U3 temps. In the case of my rev. B, the MLBB fan doesn't go nuts until the U3 hits 81 or 82C where before it would go nuts at about 76C.

[Al G]

Originally posted by Big Mac:
Not all of the Rev B. G5s use the 970FX.

Originally posted by MORT A POTTY:
they are supposed to. what doesn't?

and yes, the 970FX is a 90nm part. nobody knows anything about the GX, and nobody knows if even an MP variant exists (although signs point to the affirmative)

http://forums.macnn.com/showthread.p...hreadid=234401

[MORT A POTTY]

I stand corrected. they were SUPPOSED to only use the 970FX though. that's pretty lame of Apple to do that though.