# why is one of my hard disks much hotter than the other?

## HermanR

I have two hard disks in my computer: one PATA 80 Gb, the other SATA 160 Gb. Under any condition (system load), the temperature of the PATA disk varies around 30 degrees Celsius, whereas the temperature of the SATA disk runs much hotter: around 50 degrees Celsius. This is a (typical) output of hddtemp:

```
hddtemp /dev/hda /dev/sda

/dev/hda: Maxtor 6Y080P0: 30 C

/dev/sda: Maxtor 6Y160M0: 51 C
```

As you can see, both disks are from Maxtor and belong to the same 'family'. Both disks occupy a similar location in my case (an Antec Sonata) and have enough room to 'breathe'. The motherboard temperature is around 35 degrees Celsius, the CPU temperature stays mostly around 30 degrees Celsius.

What could be the reason for this? And, more importantly perhaps, could this have any effect on the reliability or durability of my SATA harddisk?

----------

## ianegg

I'm not sure what the problem might be, but damage to components is usually caused by changes in heat, so if it stays more or less constant it should be fine. (As long as it isn't warm enough to melt aluminium or whatever it's made from  :Smile: )

Different filesystems and partitioning schemes can have a an effect on temperature. My root and home partitions are on a sata drive, and swap var and tmp are on a pata drive (both exactly the same drive with different connections.)

I've been browsing the internet and litening to music since I got home half an hour ago, and the temperatures are as follows:

```
# hddtemp /dev/hda

/dev/hda: Maxtor 6Y080L0: 42 C

# hddtemp /dev/sda

/dev/sda: Maxtor 6Y080M0: 54 C
```

There hasn't been much activity, so maybe there's a difference between parallel/serial ata drives.

Try swapping the positions of the discs, and see what happens. You may be surprised by the thermodynamics of a PC case. (And maybe not!)

The only other thing I can think of is that the 160Gb disc may have more platters and so less internal airflow and more fristion.

(Sorry not much of an actual answer  :Smile: )

----------

## yabbadabbadont

Offtopic, but just out of curiosity, when did hddtemp start working with SATA drives?

----------

## ianegg

Well, I'm using archck sources, so it's probably in one of the libata updates. Can't give you a date though.

edit: sorry that's a pretty crap answer too  :Smile: 

----------

## HermanR

 *yabbadabbadont wrote:*   

> Offtopic, but just out of curiosity, when did hddtemp start working with SATA drives?

 

If I remember correctly, the kernel has supported this partially since 2.6.14 (but it generated a lot of error messages) and fully since 2.6.15. The support is in the vanilla kernel, as far as I know, so archck-sources and gentoo-sources (which I both use) don't make a difference as far as this is concerned.

As to my hard disk temperatures: Thanks for your comments, ianegg!  :Smile:  As soon as I have the time, I will change the locations of my hard disks and see what difference that will make. The SATA disk is where my gentoo installation resides, so it normally sees more activity than the other one (which has some other OS I use for games and the use of my not-supported scanner). But even when idle, the temperature of the SATA disk doesn't drop far below 50 degrees, whereas I've never seen the PATA disk become hotter than 35 degrees or so, even when I give it something interesting to do.

----------

## Cintra

the 50 degrees disk might just be 30 too - any way to double-check it? finger test? s.m.a.r.t perhaps?

----------

## dsd

presumably the casing of the disks is the same size - yet the 160gb disk probably has twice as many platters inside. more hardware in the same space will increase the temperature. i'm not sure if 20 degrees difference is normal or not.

----------

## Cintra

I have a pair of 160GB WDC WD1600JB-00FUA0 standing vertically next to one another (well, with a one disk gap between them) at the bottom front of my cab and they run at 30 C and 32 C while my mobo is 34 C and P4 cpu is currently 42 C at 2400Mhz

btw, if your temperature really is 51 C then you are close to the Max Operating Temperature of 55 Â°C

I did come across a Norwegian user's review of thie same disk and he was "happy" because (at the time) it tolerated running at 50 C...  :Wink: 

----------

## ianegg

Max temp 55 degrees?! Well my disc running at 54 can't be helthy! Could that account for slow performance? (lots of CPU wait cycles.) I always thought the tolerances for these things was much higher.

edit: smartmontools still doesn't support sata, ide-smart does, but the output isnt formatted nicely.

----------

## Cintra

Not a lot of factual information to be found about high temperatures on this specific model but I've come across a few user reviews moaning about failure after a year...  :Sad:  It would be interesting to know if more recent sata models have high running temperature.

----------

## Monkeh

I've got a 160GB Seagate in this which sits at 36C. 50+ is not healthy, my CPU (3ghz P4) struggles to reach that on full load for several hours, even with stock cooling.

Maxtor's have a rather high failure rate above 100GB..

----------

## ianegg

There's me thinking "Oh I have 2 80Gb Maxtors, they're been good so far, so a 200Gb Maxtor must be a good buy..."  :Smile: 

I have a small case, and can't afford a bigger one right now, so everything is a bit cramped in there. CPU idles at ~32-36 with the fan on minimum and maxes out around ~50-55 with the fan on maximum (depending on the weather.) Ambient is ~34~37. GeForce 6800 ranges between 50-70!

Anyway, I took a panel off the front and the hard drives all cooled down a bit, they're all ~35-40 now.

I hadn't checked my HDD temps before reading this thread (last time I tried, I couldn't  :Smile: ) but it's been very informative! Time to clean out the dust and get shopping for a more suitable case.

----------

## Cintra

I can recommend the black one http://www.lian-li.com/Product/Chassis/M_C_PC-6X_S_PC-60.htm  :Wink: 

----------

## ianegg

Hmm, that thing's a beast!  :Twisted Evil:  Not very pretty, but that's ok sine I'm a "function over form" man. *bookmarked* thanks  :Smile: 

----------

## Monkeh

Have a look at Silverstone cases. I ordered the TJ-06 (in black) a few days ago for my new machine. (it's a BIG case, space for 6 HDDs)

----------

## Naib

 *dsd wrote:*   

> presumably the casing of the disks is the same size - yet the 160gb disk probably has twice as many platters inside. more hardware in the same space will increase the temperature. i'm not sure if 20 degrees difference is normal or not.

 

I will have to agree with this. the amount if power a motor outputs (and thus draws) is equal to the Torque times the speed.

Assuming both drives are the same speed 

Increasing the number of platters will increase the Moments of Inertia of the load as well as its mass. This will increase the the Torque requirement

Thus for higher capacity drives the power drawn MUST go up

----------

## Monkeh

 *Naib wrote:*   

>  *dsd wrote:*   presumably the casing of the disks is the same size - yet the 160gb disk probably has twice as many platters inside. more hardware in the same space will increase the temperature. i'm not sure if 20 degrees difference is normal or not. 
> 
> I will have to agree with this. the amount if power a motor outputs (and thus draws) is equal to the Torque times the speed.
> 
> Assuming both drives are the same speed 
> ...

 

20 degrees and right under the max op temp is really pushing it however.

----------

## Cintra

ref big sata drives, from http://www.hothardware.com/viewarticle.aspx?page=2&articleid=776&cid=4 from lead at http://www.theinquirer.net/?article=29149

 *Quote:*   

> ..we actually took an infrared temperature meter to the WD1500 drives and compared surface temps under load versus the WD740 and a pair of 250GB Maxtor DiamondMax 10 drives.  Both the WD740 and WD1500 series Raptors recorded max temps in the 105o - 109oF range under a full load HD Tach Write test. 

 i.e ca 41 C

Mvh

----------

