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zign · Jul 31, 2005, 02:51 PM

I bought 20" iMac G5, 2.0Ghz, 2Gb RAM and I was wondering what other users pcu tempretures are. I use temperature monitor and it shows 50-55C with processor performance set to automatic and just a few prog running. The HD temps are 45-55C. Are these normal?

italiano · Jul 31, 2005, 03:13 PM

mine is at 52/125 right now with just Safari running - seems normal to me... I have the 20" 1.8 ghz.

Fonzie · Aug 1, 2005, 12:11 PM

My CPU temp is as high as 61 degrees celcius with iTunes, Safari, iChat, Mail and Pixadex running. I have a Rev.A iMacG5 1.8ghz 17" and my cpu setting is set to Automatic. I have a feeling that the temp is quite high.

I have 1024MB ram in it.

Recontech · Aug 1, 2005, 12:31 PM

Thats funny, I have a 1.6ghz Rev. A 17" G5, and with processor performance set to Highest, with Safari, AOL, AdiumX, and Azureus running, my temp was about 68 degrees C. Same stuff running with processor set to "Automatic" its at 62 degrees.

discotronic · Aug 1, 2005, 01:07 PM

I can't remember what the temps where on my iMac. On my PowerMac G5 1.8GHz SP the temps run at around 45 degrees C. I did a test the other day to see what it would run at with a slightly heavy load. I burned a DVD using Toast, had 2 Quicktime movies playing, iTunes with Visualizer, Safari, did a virus scan with that free Anti-virus scanner (can't remember the name), and I was downloading a 600mb + file. The temp only went up to 58 degrees C.

I have the system in an enclosed cabinet which I usually leave the door open. I kept the door shut for the test.

Fonzie · Aug 1, 2005, 01:19 PM

Originally Posted by Recontech

Thats funny, I have a 1.6ghz Rev. A 17" G5, and with processor performance set to Highest, with Safari, AOL, AdiumX, and Azureus running, my temp was about 68 degrees C. Same stuff running with processor set to "Automatic" its at 62 degrees.

I wish I could set my Rev.A on Highest. but the damn thing sounds like a jetplane taking off. Good for you.

Recontech · Aug 1, 2005, 01:19 PM

Wow, I am assuming due to the design and fans, etc... That the powermacs are obviously going to run much cooler...

PBG4 User · Aug 1, 2005, 03:42 PM

Originally Posted by Fonzie

I wish I could set my Rev.A on Highest. but the damn thing sounds like a jetplane taking off. Good for you.

You're lucky. For some reason, my fans won't run fast enough to cool off my CPU (20" 1.8GHz) and on hot days my iMac will put itself to sleep. When I wake it back up, the fans go full blast for about 1/2 a second, then the OS steps them down which causes the iMac to go back to sleep after about 5 seconds. I have to wait for some time until the computer is cooled enough to use again. I don't want to but I think I have to call Apple.

Recontech · Aug 2, 2005, 12:57 AM

I wonder if there is a way to help cool these G5 iMacs... I'd love to always set it to Highest, but yeah, Jet planes galore...

zign · Aug 3, 2005, 05:48 AM

So my temps are normal then. Good.

I don't need highest. It runs good enough on automatic, which, as far as I understand, can set it to highest when needed anyway.
I wouldn't mind creating some extra airflow. Maybe extra fans you can just turn on when heavy tasks are carried out. I don't care about the noise. 45-60C is fine, but when it goes above 70C I worry. When I use it for web-browsing, itunes, word processing and light image editing, the temps stay at around 50, which is fine by me. My Athlon 64 was much hotter, eventhough I had $150 cooling system installed on the processor.

zign · Aug 3, 2005, 05:53 AM

How do high temps affect the screen? Just interested.

Fonzie · Aug 3, 2005, 06:45 AM

zign, I don't know about the screen. But I had my iMac in for repairs after 6months of use. I got my mainboard replaced and also the fans(which didn't help with the noise). I do have some sort of feeling that the heat is responsible somehow. It can't be good having the whole computer sit behind the screen like that. If one just gently touches the screen with their hands - the screen is a little hot. But maybe that's normal.

zign · 04:09 PM

To Fronzie: You Rev A then. I thought that some of the problems were fixed in Rev B. At least I hope so. I love my iMac (because it looks cool

) Most of the problems reported on the net are Rev A related.
I think I will install a small fan which will provide cool air to the back of the mac so that it sucks cold air in. I think that because of my setup the air around the computer area gets quite warm. Here's my setup:

I think because of the shelf just above the mac the warm air coming out of the top doesn't get away.

OogaBooga · Aug 3, 2005, 10:05 AM

Hmm... we haven't had any problems with our three 17" iMac G5s at work, and they're on 24/7. I can't ever hear them either, but that's because there's always some sort of music playing in the work environment.

zign · Aug 3, 2005, 10:12 AM

Originally Posted by OogaBooga

Hmm... we haven't had any problems with our three 17" iMac G5s at work, and they're on 24/7. I can't ever hear them either, but that's because there's always some sort of music playing in the work environment.

I am not having problems. I just want to avoid them in the future

I don't mind the noise. We basicly have a G5 laptop here, so the fans are to do the job. Even then I wouldn't even call it
noise. My old PC with Athlon 64 made 10 times more noise. I think that when people read that it is whisper quiet and expect to hear nothing at all and so they complain.

So you keep your iMacs on 24/7 and none of them had problems? That's good to hear

I am not a fun of shutdown function

Fonzie · Aug 3, 2005, 03:02 PM

My Mac is free from any cupboards or whatever they are called. I have all sides free. Still the temp rises to mid 60s when just doodling.

hoodmulti · Aug 3, 2005, 10:27 PM

Originally Posted by zign

How do high temps affect the screen? Just interested.

The hot temp doesn't affect the screen directly, but it does affects the electonics behind it for sure, since electonics are very sensitive to temperature. It affected those capacitors of the display card in the iMac G5, whats worse is that Apple had got a whole bunch of dodgy one into the midplane / logic board, thats why there are so many iMac with problems.

Here is another discussion explains the problem with the problem with the capacitors:
http://forums.macnn.com/showthread.php?t=262088

as2 · Aug 14, 2005, 10:36 AM

With performance set to automatic, my processor is running at nearly 90°C.

That's too hot surely??

cleanup · Aug 15, 2005, 01:02 PM

as2: Hmm, yes.

After just waking up from sleep, my iMac G5, with Finder, Safari (one page) and iTunes (not playing) running, my CPU temp is about 58.

It's normally around 60 - 65. But under heavy load it can top 70.

The quietness of the iMac G5 is nice, but I think Apple could have done a better job on its cooling...

Funny thing, when I place my hand next to the corner of the air vent (where most of the air comes out), the air feels cool to the touch, but that might be because I was just playing drums, so my hands feel warm and sweaty.

PBG4 User · Aug 15, 2005, 03:07 PM

Originally Posted by as2

With performance set to automatic, my processor is running at nearly 90°C.

That's too hot surely??

My iMac was putting itself to sleep when it got past 89C, so see if your iMac does that too.

I did an SMU reset last weekend (gotta push a button on the motherboard

) and that seems to have lowered my CPU temps by about 5C. My computer no longer puts itself to sleep, but now it runs around 85C constantly.

I downloaded XRG and it's reporting my CPU fan is running at 4400RPM and my other two fans are running about 1500RPM. Now none of the fans sound like they're screaming faster than the other ones so is it possible the RPM monitor is off which is causing my CPU to get too hot? Is the CPU fan the one that's tied to the motherboard? I'd love to be able to get a replacement if at all possible.

Ozzpot · Aug 17, 2005, 08:03 AM

My RevB iMac G5 2.0ghz 17" runs at about 85°C normally, and often tops 100°C (232°F) during heavy Photoshop sessions for example. The fans run full blast for a while afterwards to cool it down, other than that no problems. I think people make too much of heat issues IMO.

Chinasaur · Dec 20, 2005, 08:43 AM

I was wondering... My 20" 2G and my friends 17" 1.8 run at 192F doing distributed.net crunching. Both are Rev B's.

For any CPU this is waaay high but seems to be "ok" for the PowerPC.. at least it seems to be "normal" for the imac

Dwillis03 · Dec 20, 2005, 10:26 PM

Where the heck do you check your temp on the G5?

<----- PC guy

Thanks.

Chinasaur · Dec 21, 2005, 11:42 PM

ThermographX - http://www.macupdate.com/info.php/id/13019

Eug Wanker · 02:16 AM

CPU: 72°C

The CPU was at about 90% utilization.

macintologist · Feb 10, 2006, 02:43 AM

Do the Intel macs have this problem?

Irken Invader · Feb 10, 2006, 03:16 AM

Originally Posted by macintologist

Do the Intel macs have this problem?

Mine doesn't. This 2.0 is whisper quiet next to the 2.0 G5 (rev. B) it's replacing. The G5 gets up to 83ºC under load, and its hair dryer goes full tilt at the slightest suggestion of work. It really is ridiculously loud in comparison to the Intel iMac, especially since it's one of the G5s with a buzzing CPU fan.

Also interesting is that the Intel machine is as quiet at 200% utilization as it is at idle, and the air from the top vent isn't much warmer than room temperature in either case.

Eug Wanker · Feb 10, 2006, 08:54 AM

Originally Posted by macintologist

Do the Intel macs have this problem?

Not sure if it is a problem, because my G5 iMac is actually fairly quiet at 72°C. It's not whisper quiet though, so the Intel Macs do seem to have an advantage there.

PBG4 User · Feb 10, 2006, 08:59 AM

Apple replaced the logic board and power supply in my G5 iMac. My temps now hover in the 60 - 70C range. They don't get anywhere near the 90C range I was seeing last summer (see my earlier posts in this thread). After my last (3rd) repair my iMac G5 is finally "whisper quiet".

osxrules · Feb 10, 2006, 09:46 AM

I keep wondering why computer manufacturers still use fans at all. I have a mini fridge and the unit at the back is pretty small and can even freeze my juice on a cold day. It's not all that noisy either comparing to the G5 fan noise (I use a quad G5 and it certainly is like an aircraft). I'm sure the geniuses who can put a million transistors on a chip the size of a stamp can manufacture a cooling device based on a similar concept used in a fridge that makes practically no noise and just sit it right on top of the chip instead of blowing air over it. Most DIY liquid cooling kits are difficult to install and use water. If my chemistry serves me right, they use freon in fridges don't they?

Eug Wanker · Feb 10, 2006, 10:06 AM

Originally Posted by osxrules

I keep wondering why computer manufacturers still use fans at all. I have a mini fridge and the unit at the back is pretty small and can even freeze my juice on a cold day. It's not all that noisy either comparing to the G5 fan noise (I use a quad G5 and it certainly is like an aircraft). I'm sure the geniuses who can put a million transistors on a chip the size of a stamp can manufacture a cooling device based on a similar concept used in a fridge that makes practically no noise and just sit it right on top of the chip instead of blowing air over it. Most DIY liquid cooling kits are difficult to install and use water. If my chemistry serves me right, they use freon in fridges don't they?

Fridges aren't magic. My fridges are moderately noisy, and they put out a lot of heat. It's just that the entire back of the bridge is one big radiator so no fans are needed. Your G5 Quad uses liquid cooling too, but do you really want the entire outside of your Power Mac to be a radiator too?

No? Well then it makes sense to make the radiator much smaller, and blow air through it.

saxondale. · Feb 10, 2006, 10:44 AM

CPU: Highest
G5 1.9GHz
2.5GB RAM

CPU: 56C
HDD: 35C

Eug Wanker · Feb 10, 2006, 11:00 AM

Originally Posted by saxondale.

CPU: Highest
G5 1.9GHz
2.5GB RAM

CPU: 56C
HDD: 35C

Idle or under load?

My 72 was a G5 2.0 under heavy load (backing up a hard drive and using Handbrake to encode a DVD to an H.264 file at the same time), but the fan was still relatively quiet, albeit not whisper quiet. Ambient temp is about 21.

When idling it's much cooler (and the fan is quieter).

I do wonder how accurate these CPU temp measurements are though, especially across platforms. Nonetheless, the new Core Duo machines seem great for power. Cooler running and dual-cores. I look forward to 2007 when I get my dual-core Intel iMac.

BTW, if I don't set the CPU to "Highest" Handbrake encodes at roughly half the speed. I guess the "Automatic" setting doesn't work very well for Handbrake. In contrast, CPU render speeds are exactly the same for Cinebench regardless of that setting.

saxondale. · Feb 10, 2006, 01:52 PM

That was idle, under load:
CPU: 66C
HDD: 50C

BikerJonTN · Feb 10, 2006, 03:26 PM

My iMac Core Duo doesn't have the processor throttle option in the Energy Saver preferences pane. Am I missing something?

Eug Wanker · Feb 10, 2006, 04:16 PM

Originally Posted by BikerJonTN

My iMac Core Duo doesn't have the processor throttle option in the Energy Saver preferences pane. Am I missing something?

AFAIK, the Core Duo's power management features are significantly more sophisticated than the G5's, and a user-adjusted "Highest" vs "Automatic" setting would likely be pointless.

Tuishimi · Feb 11, 2006, 02:39 AM

...and fans are at about medium speed. I had been playing a game not too long ago, tho'.

Both of our G5 iMacs seem to run hot and noisy. But in fairness, the fans on my newer 20" G5 iMac are much quieter and do not whine like the fans in my wifes Rev A. 17" G5 iMac.

osxrules · Feb 12, 2006, 12:30 PM

Originally Posted by Eug Wanker

Fridges aren't magic. My fridges are moderately noisy, and they put out a lot of heat. It's just that the entire back of the bridge is one big radiator so no fans are needed. Your G5 Quad uses liquid cooling too, but do you really want the entire outside of your Power Mac to be a radiator too?

No? Well then it makes sense to make the radiator much smaller, and blow air through it.

It's really cold where I live right now so a radiator wouldn't go amiss

. You're right that a normal fridge wouldn't be much good but they have to cool the volume of a whole food storage unit. A CPU fridge would have a much smaller volume to cool so it could be far smaller.

I wonder if the G5 being liquid cooled is why it takes longer to start up. My Mini boots quicker than the G5 Quad.