Hard drive seems way too hot!

XRG shows the external, Apple supplied sensor. You can see the SMART sensors with Temperature Monitor. They are too high for any hard disk to operate reliably over a couple of years.

I am about to install a new hard drive (sent from Apple). Currently, I'm running off of a 'temporary, old' hard drive. My original Seagate 160 GB SATA failed a week ago.

I have an iMac G5 20" (Rev 'A'). It's 8 months old.

My conclusions are:
- There's a definite design flaw in cooling the hard drive in all iMac G5s to date, excluding the new version, which was just announced. I hope Apple fixed this. It's far more important than the new eye candy.
- My machine is running at the following temperatures: CPU around 60, HD (Apple sensor around 53, SMART sensor around 65), all Celsius
- I have no problems with the fan speed and/or noise, but this does not mean that the machine is not going to fail again. My RPMs are: CPU around 1700, HD around 2000, System around 1700.
- Due to a failed HD, I experimented with repositioning the HD sensor. I moved it to the surface of the hard drive, which resulted in SMART sensor (internal HD sensor) reporting temperatures around 58 degrees, but this also made the fans go crazy. Actually the HD was constantly warming up and down, between 48 and 58 degrees. This happened in a period of 30 minutes.
- There is a bottom limit set for the RPM of the hard drive fan. It's set to 1800. I would like to experiment with setting this higher, just to get the HD cooler. There's no way to do this that I know of. Does anyone know of a low level way to set the low fan RPM limit for any of the G5 fans?
- I'm really not able to trust the machine anymore. It failed on me twice in the last 6 months. First it was the inverter, now the hard drive.

I would be willing to cool down the hard drive using some kind of internal cooling system, like an additional fan. There are no free power supply connectors inside.

I was also thinking about cooling it down with an additional cooling cage (like processor case, modified). I'm still thinking of it.

Any thoughts? Anyone tried this? I have seen the external fans mounted on the G5s.

Matevz, my hard drive has run consistently at 55C or 131F since the day I bought it last March using the external Apple sensor. Hard drive speeds stayed around 2000 rpm which isn't that far off the lower limit. I drew the conclusion that I was well with in the operating temp range given that the fans were not running wildly. Now I don't know if I am at the upper limit of the HD oper. temp or I'm getting a bad reading from XRG. What is "Temperature Monitor" and where do you get it? I admire your relocation of the HD sensor and did you eventually put it back to its original position? I have seen the external mounted fans but I have trouble taking the ax to the machine when I have Apple Care. Personally, I think relocation of the sensor to a location (hotter) that operates the fans at a higher RPM is the best solution.

Dick

Richard...interesting pic...I have been using a fan from Lasko to do the same thing.It is small , quite , cheap and actually matches my iMac in design.

I have aimed the fan at the same spot as the fan on your link and it really cools things down quickly by simply dissapateing the heat on the back of the case

As an added benifit it cools down my iSight cam which is mounted on top of my iMac

HD temp runs around 120 F...CPU around 135 F to 145 F....highest so far 166 F

http://www.laskoproducts.com/fans/model_4904.html

dave

Dick,

My line of thought is the following.

Yes, the external Apple sensor provides temperatures on the outside of the internal hard disk. SMART sensor, which is built in, tells temperature of the hard drive. This temperature is indeed homogeneous, throughout the drive, in most cases when the temp is not changing a lot.

And the SMART hard disk sensor is what worries me. I get 63-67 Celsius temperature reads, depending on the workload. I do not get over 54 Celsius on the Apple provided sensor. In ANY way, this is too hot for the drive to handle in the long run.

I have moved the sensor to two locations on top of the drive. This caused a major fluctuations in temperatures, since the fans were lagging way behind the heat cycle.

Let me illustrate:
- Start up, HD temp normal, fans normal
- 10 minutes, HD temp rises to 55 (Apple sensor)/65 (SMART)
- Liftoff time, HD fan to 5000-6000, system, CPU fan to 4000
- Fans cool the HD down (48 (Apple sensor)/55 (SMART)), stop blowing
- Fans running slow, everything normal, HD temp again going up to 55
- Loop

So, machine was in constant full blowing - no blowing cycle and rising/falling HD temps.

I believe that this is even worse than having a hard drive constantly at 65 degrees. I also believe that SMART sensor is the authoritative one. My hard drive is currently running at 67 degrees Celsius, which is way too much for it to survive. It's rated to go up to 60 C, ambient temp, so we're really pushing the limit. My RAID array on a Windows Server is running four (4) drives, stacked together, with fans blowing through them at 38 C.

That's why I thing the cooling system on the iMac G5 is flawed.

You can find Temperature Monitor link on Google. It's a free little app, showing HD, CPU and HD SMART temperature.

Regards,
Matevž.

Thanks for the info Matevz. Dave has implemented a simple solution thats non destructive and takes 10F off the HD and cpu temps. I have just plugged the fan in and will let you know what happens. PS I stayed for a month at the Slon Hotel in Ljubljana. Great town.

Dick

Richard...at my local grocerie store of all places...takes alot longer for the iMac to heat up and it cools down a lot faster...another bonus is it masks the everpresent CPU fan whine with a steady , even sound of air moving

Googled Lasko and found the fan stats there...

I know we shouldn't have to do this...but this iMac sits in front of me and I will help it along when I can
dave

Dave I plugged an old Lasko fan in (ugly as a bucket of worms), aimed it accordingly, and have dropped my hard drive temp from 131F (55C) to 113.9 F (45.5C) My cpu temp has dropped from 150F to 145F. This is measured using XRG. I am impressed. Did you buy the fan over the counter? The fan has a 12" D blade and it is a little much, so I am going to get the same one you use. Apple should have mounted an aluminum finned heat sink on the back of the unit or incorporated it in their housing design with a small blower and they would be able to shed a lot of heat.

Dick

Richard...my temps come from TemperatureMonitor app..

with the 17" iMac at least the CPU > RAM > Hard Drive all are on the left side (as you face it) in my case that is where the back stays the hottest..

regular house type fans do not direct airflow intense enough to dissapate the heat from inside the iMac (my observation)...the fan I am using produces a tight blast at the back of my iMac not the intake or the exhaust

dave

Dave, the noise masking is a bonus. I have my fan on low an it's masking the whine of the Apple fans plus my hard drive and cpu are sticking at 114F and 145F respectively. With the correct fan it will improve.

Dick

Matevz, the HD temp dropped from 131F (55C) to 113.9F (45.5C) in under 3 minutes and back of the casing is only slightly warm to the touch. Apple should have incorporated an aluminum heat sink in the case behind the HD to help dissipate the heat. Cheap fix.

Dick

A lousy desk fan to boot. I am going to get one like Dave's that has more of directed flow (blower) as opposed to the propeller fan I tried out. The propeller fan ids to large and I am worried about interfering with the exhaust port on the upper rear of the casing. Yes, my HD temps typically ran at 131F and its sitting here now at 117.5F (I re directed the fan down because of the exhaust port). A heat sink would have been simple for Apple. Incorporate it right in the casing, aluminum and finned and throw a housing and blower at it. You would never see it from the front. This took 14F out of it with out cracking the box. I don't think there is a good solution internally. I think you hit the nail on the head with the heat sink. You could probably buy a an electrical heat sink and mount it ( I would tape it first) on the case behind the HD and with a little air movement, viola.

Dick