Why mount the hard drive like that?

Silencing hard drives, optical drives and other storage devices

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spcr2u
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Why mount the hard drive like that?

Post by spcr2u » Sun Aug 31, 2014 7:15 pm

Doesn't anybody know that a typical 3.5" Sata 7200rpm hard drive gives off way more heat from the bottom or circuit board side than the top? Why would anybody in their right mind put the heat generating side flush against a flat surface not letting the heat escape easily? I see this endlessly in case design. Am I missing something? Do people think that their monitor will display things upside down if their hard drive is upside down? When the circuit board side is facing out they could have a 120mm fan running silently at 5 volts cooling it very well. But you never see this. What we really need is a heatpad that is cooled somehow and is placed against the circuit board side.

Think of ever heat generator in the case. CPU, Video card, mechanical hard drive and power supply (and sometimes the chipset and ram). You want to cool these pieces independently if possible with external air, NEVER with internal, warmed air. The layout that is smart makes this so easy. But you almost never see this today. So many case designs are cooking that air inside then using it to try to cool something. Brainless.

xan_user
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Re: Why mount the hard drive like that?

Post by xan_user » Sun Aug 31, 2014 7:37 pm

personally i prefer vertical (on edge). take advantage of natural convection.

CA_Steve
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Re: Why mount the hard drive like that?

Post by CA_Steve » Sun Aug 31, 2014 7:38 pm

Topic moved to the Silent Storage forum.

Vicotnik
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Re: Why mount the hard drive like that?

Post by Vicotnik » Sun Aug 31, 2014 10:14 pm

With a fan in front of the HDD it doesn't matter how it's mounted.

From a cooling standpoint everything should have fresh air. But other things matters as well, like dust accumulation and esthetics. I prefer a clean case with less fans and smart internal airflow.

Also, today the trend is towards less power hungry stuff. RAM for example doesn't really need heatsinks, much less fresh air from outside. It's all about getting the right case for the right components.

spcr2u
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Re: Why mount the hard drive like that?

Post by spcr2u » Mon Sep 01, 2014 11:22 am

xan_user wrote:personally i prefer vertical (on edge). take advantage of natural convection.
That makes sense indeed. But I wasn't mentioning that. My point was that if most of the heat comes from the circuit board side, no thinking person would mount that flat against a surface that is severely restricting airflow. Is so easy to just flip it around. Feel your hard drive when operating: You'll see that its always much warmer on the circuit board side than on the other side. And no appreciable heat comes out of the sides.

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Re: Why mount the hard drive like that?

Post by xan_user » Mon Sep 01, 2014 4:44 pm

why not run a test? batch copy/AV scan a hdd with the bottom up and bottom down (and maybe one on end) and see what the actual temps are. i bet you dont see more than 2 degrees C dif max. and even if it was 5 degrees dif, what did you really gain? the same heat has to be dissipated from the case, and a drive running 5 degrees cooler wont help the system, as long as the drive is operating within its designed temperature specs.

spcr2u
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Re: Why mount the hard drive like that?

Post by spcr2u » Mon Sep 01, 2014 4:47 pm

The temperatures are hugely different because you can cool the circuit board side with a fan if its exposed! About 7-10c difference!

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Re: Why mount the hard drive like that?

Post by xan_user » Mon Sep 01, 2014 5:35 pm

spcr2u wrote:The temperatures are hugely different because you can cool the circuit board side with a fan if its exposed! About 7-10c difference!
are you saying same drive , in the same bay, in the same PC, with same fan, runs 10*cooler depending on whether its upside down? that very hard to believe.
but, ok. ill go with it, what does that-10c dif gain you?
what is the max temp with hdd right side up? is it within the temperature specs for the drive? if yes than you've gained nothing. it wont last longer, nor will it run faster if its run cooler. shoot, with the bottom up you might even get more dust accumulation, on the "bottom", so after a time temps might go back to where they would be with traditional mounting, they might even get worse.

Im not trying to bust your chops. this might help if you had a really poor airflow case, with a drive placed in some isolated corner. But in most cases you'd gain nothing by changing the drive mounting position.

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Re: Why mount the hard drive like that?

Post by Vicotnik » Mon Sep 01, 2014 10:03 pm

spcr2u wrote:And no appreciable heat comes out of the sides.
Actually, a lot of heat exits from the sides. That why a hard mounted HDD is easier to cool than a suspended drive; the case acts like a heatsink. Flipping the HDD over exposing the circuit board is recommended in an environment where the airflow is low and the drive suspended, I give you that.

spcr2u
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Re: Why mount the hard drive like that?

Post by spcr2u » Tue Sep 02, 2014 4:30 am

> The temperatures are hugely different because you can cool the circuit board side with a fan if its exposed! About 7-10c difference![/quote]
are you saying same drive , in the same bay, in the same PC, with same fan, runs 10*cooler depending on whether its upside down? that very hard to believe.
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If the drive is mounted with the heat generating side crammed against a flat surface it will have very little circulation of air AND you cannot cool it at all with a fan.
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> but, ok. ill go with it, what does that-10c dif gain you?
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Read the Google survey of failing hard drives. The top reason for drive failure is variance of temperature. Losing your hard drive for most users unless incredibly adept at backup which few of us are, means many hours of re-installing not to mention losing data, often recent.
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> what is the max temp with hdd right side up? is it within the temperature specs for the drive?
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You expect truth from a company selling something? I don't.
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> if yes than you've gained nothing. it wont last longer, nor will it run faster if its run cooler. shoot, with the bottom up you might even get more dust accumulation, on the "bottom", so after a time temps might go back to where they would be with traditional mounting, they might even get worse.
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Don't believe somebody selling something. Believe others that use their products. There, truth prevails far more.
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> Im not trying to bust your chops. this might help if you had a really poor airflow case, with a drive placed in some isolated corner.
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If you mount the heat generating side flush against something you have almost zero airflow. If you mount it horizontally, you severely disrupt airflow. Drives should be mounted vertically for the heat to easily escape and rise and exit the case. Every case design is lousy these days. The major heat generating areas should be isolated and each cooled with external air and that heated air needs to be expelled from that area immediately. I've never seen a single case that obeys this pragmatic logic. Not a one. If you have, please send a link. That would be a welcome change from the mindless case design we have today. CPU, video card(s), mechanical hard drives, power supply and to a lesser extent memory and chipsets. So you need 5 areas to address really.

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Re: Why mount the hard drive like that?

Post by nutball » Tue Sep 02, 2014 6:23 am

spcr2u wrote:Read the Google survey of failing hard drives. The top reason for drive failure is variance of temperature.
The Google hard-drive survey paper wrote: We first look at the correlation between average temperature during the observation period and failure. Figure 4 shows the distribution of drives with average temperature in increments of one degree and the corresponding annualized failure rates. The figure shows that failures do not increase when the average temperature increases. In fact, there is a clear trend showing that lower
temperatures are associated with higher failure rates.
Only at very high temperatures is there a slight reversal
of this trend.
...
Overall our experiments can confirm previously re-ported temperature effects only for the high end of our
temperature range and especially for older drives. In the
lower and middle temperature ranges, higher temperatures are not associated with higher failure rates.
...
One of our key findings has been the lack of a consistent pattern of higher failure rates for higher temperature drives or for those drives at higher utilization levels.
...
Although our data do not
allow us to conclude that there is no such correlation,
it provides strong evidence to suggest that other effects
may be more prominent in affecting disk drive reliability in the context of a professionally managed data center
deployment

spcr2u
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Re: Why mount the hard drive like that?

Post by spcr2u » Tue Sep 02, 2014 6:29 am

See? Google supports me.
Before operation the drive will be at ambient temperature, which for most of us is room temperature most of the time. So the last thing you want is to raise that temperature from faulty placement. Mount a surface flush and the heat has little ability to escape.

nutball
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Re: Why mount the hard drive like that?

Post by nutball » Tue Sep 02, 2014 6:43 am

spcr2u wrote:See? Google supports me.
No it doesn't. You are misinterpreting the words.

xan_user
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Re: Why mount the hard drive like that?

Post by xan_user » Tue Sep 02, 2014 7:02 am

then why does google build its servers like this?
Image

lodestar
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Re: Why mount the hard drive like that?

Post by lodestar » Tue Sep 02, 2014 7:45 am

The fact that that image was originally from an article dated April 1st tells its own story...

xan_user
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Re: Why mount the hard drive like that?

Post by xan_user » Tue Sep 02, 2014 9:52 am

lodestar wrote:The fact that that image was originally from an article dated April 1st tells its own story...
not really. google has a longish history of having both fictitious and real press releases on the first of April.

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