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Lokheed

macrumors regular
Jun 10, 2009
202
0
You aren't the only one. I was just looking at iFixIt's teardown and there aren't any air vents on the bottom. There's just that one on the back like you mentioned.

Can anyone explain?

Yeah, pretty much. And how does air get drawn in from the bottom, it's a sealed unit. There aren't any holes in the plastic base plate. Where is it pulling the air in from exactly? Through the plastic??? The sides where the plastic meets the aluminum chassis? Because that part is already elevated off the desk (by about 2 cm), and you know, again sealed. You ever put your finger on the end of a straw and try sucking on it? Not much going through is there?
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
I cannot believe that there are those who do not notice the rubber seal in the bottom plastic bit and that it does not cover the antenna area......

In other words: If you take a moment to investigate then you'll see that the air is being sucked in through the metal grill around the antenna through the thin gap around the whole of the bottom plate which is cleverly held in place by three standoffs. Duhhhh
 

tbayrgs

macrumors 604
Jul 5, 2009
7,343
4,867
I cannot believe that there are those who do not notice the rubber seal in the bottom plastic bit and that it does not cover the antenna area......

In other words: If you take a moment to investigate then you'll see that the air is being sucked in through the metal grill around the antenna through the thin gap around the whole of the bottom plate which is cleverly held in place by three standoffs. Duhhhh

Thank you for clarifying for the clearly ill-informed.

Yeah, pretty much. And how does air get drawn in from the bottom, it's a sealed unit. There aren't any holes in the plastic base plate. Where is it pulling the air in from exactly? Through the plastic??? The sides where the plastic meets the aluminum chassis? Because that part is already elevated off the desk (by about 2 cm), and you know, again sealed. You ever put your finger on the end of a straw and try sucking on it? Not much going through is there?

Buddy, time to quit while your ahead. Ooops, too late.
 

Lokheed

macrumors regular
Jun 10, 2009
202
0
I cannot believe that there are those who do not notice the rubber seal in the bottom plastic bit and that it does not cover the antenna area......

In other words: If you take a moment to investigate then you'll see that the air is being sucked in through the metal grill around the antenna through the thin gap around the whole of the bottom plate which is cleverly held in place by three standoffs. Duhhhh

So around the rim of the bottom plate? The part of the unit that is roughly 2 CM off the table already? That part? How much air do you think it sucks in that it needs to be lifted another foot off the desk?

So let's put it to the test (hence the late reply). I ran the new 2011 Mini elevated 6" above my desk using a round PVC tube (3" in diameter) for 4 hours. Idle temps were 45-47 C. Standard use (surfing the net, reading emails, playing iTunes, etc.) saw it jump between 47-54 C (while the jumps in temp seemed high and abrupt, they quickly descended just as fast as they ascended). High load saw it rest at 71-74 C (20 minute encode of a TV show using Handbrake which saw all 4 threads 100%). Ambient air stayed constant at 38-39 C for the length of the test.

And then we have the 4 hours of standard use to compare (which I just now finished). The only difference was the removal of the PVC tube which saw the Mini sitting right on the desk. Drum roll… The freakin' same! I reiterate: Temps were identical in all test cases (okay except for the light use, which varied in temperature, but retained the same high and low values throughout), whether the Mini was elevated or not.

Temperatures were collected using Marcel Bresink's Temperature Monitor (4.94) and confirmed to be the same as iStat Nano's readings before data was collected. The temperature above is collected from the CPU diode sensor only (and the ambient air temperatures were checked for consistency), which is what I'm assuming people are arguing will see a drop.

So there you go. And that's why you should always collect data rather than convincing yourself something has an effect...
 

cstanmac

macrumors newbie
Aug 13, 2011
4
1
I cannot believe that there are those who do not notice the rubber seal in the bottom plastic bit and that it does not cover the antenna area......

In other words: If you take a moment to investigate then you'll see that the air is being sucked in through the metal grill around the antenna through the thin gap around the whole of the bottom plate which is cleverly held in place by three standoffs. Duhhhh

Yes, when the cover is on, the red part will be sealed as shown below. Air travel through as MJL said.

mini1.jpg


And the air should be sucked in from the front as circled below. Not the back as mentioned in ifixit.

mini2.jpg
 
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MJL

macrumors 6502a
Jun 25, 2011
845
1
So around the rim of the bottom plate? The part of the unit that is roughly 2 CM off the table already? That part? How much air do you think it sucks in that it needs to be lifted another foot off the desk?

So let's put it to the test (hence the late reply). I ran the new 2011 Mini elevated 6" above my desk using a round PVC tube (3" in diameter) for 4 hours. Idle temps were 45-47 C. Standard use (surfing the net, reading emails, playing iTunes, etc.) saw it jump between 47-54 C (while the jumps in temp seemed high and abrupt, they quickly descended just as fast as they ascended). High load saw it rest at 71-74 C (20 minute encode of a TV show using Handbrake which saw all 4 threads 100%). Ambient air stayed constant at 38-39 C for the length of the test.

And then we have the 4 hours of standard use to compare (which I just now finished). The only difference was the removal of the PVC tube which saw the Mini sitting right on the desk. Drum roll… The freakin' same! I reiterate: Temps were identical in all test cases (okay except for the light use, which varied in temperature, but retained the same high and low values throughout), whether the Mini was elevated or not.

Temperatures were collected using Marcel Bresink's Temperature Monitor (4.94) and confirmed to be the same as iStat Nano's readings before data was collected. The temperature above is collected from the CPU diode sensor only (and the ambient air temperatures were checked for consistency), which is what I'm assuming people are arguing will see a drop.

So there you go. And that's why you should always collect data rather than convincing yourself something has an effect...

Thank you for testing to see if it makes a difference, did you check if the fan rpm stayed the same, it will be very usefull to know.

I just wonder how many people never move their computer off their place. Have you ever seen how much dust collects there? I also wonder how many people place their computer on their desk and have some cloth underneath it.... And if you place the computer just 'as is' on the desk, did you not notice how easily it slides around dragged by the cables in the back? A couple of rubber feet will just ensure less dust collection and less blocking of the air intake and ensure that it does not skid all over the place. And an added bonus: less mechanical noise transfer to your desk. It is not always only about temperature although I always did this with my Thinkpads and it made a difference there, particularly when I was doing simulations running 12+ hours at 100% CPU load. It prevented the temperature rising above 65 C which I consider to be the max temperature allowed for longevity of electronic equipment (based on military standards).
 

lilsoccakid74

macrumors 6502
Apr 13, 2010
282
0
High load saw it rest at 71-74 C (20 minute encode of a TV show using Handbrake which saw all 4 threads 100%). Ambient air stayed constant at 38-39 C for the length of the test.


Thats very interesting, since my mini gets to 95*C while running 4 threads at 50% from a HD netflix movie.
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
The "inside" of the plastic base, you can clearly see the rubber seal that stops the air getting directly into the area outlined by the red line in the previous post.

philipma1957: Many thanks for the link to those excellent feet, these arrived today.
 

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philipma1957

macrumors 603
Apr 13, 2010
6,365
251
Howell, New Jersey
The "inside" of the plastic base, you can clearly see the rubber seal that stops the air getting directly into the area outlined by the red line in the previous post.

philipma1957: Many thanks for the link to those excellent feet, these arrived today.

I have 5 pairs of black ones on order. I have a few clear ones on hand. They truly kill two birds with one stone. No slippage and they raise the mini for better air flow.
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
Added benefit of having those feet: I've now got a place to affix the Windows 7 license sticker.... IF (big IF ;) ) you are adventurous then you can drill a series of small holes in the black area and then use a vacuum cleaner's exhaust airfilter cut to size between the black part of the base base and the grille around the antenna. No more inside dust and no need to clean the inside of the computer ever, just replace the filter once a year.

I've build tube amplifiers in the past and if you've got a drill template then you can space the holes nicely and have a professional looking job.
 
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hardax

macrumors regular
Jan 16, 2008
193
57
New Hampshire
Thank you for testing to see if it makes a difference, did you check if the fan rpm stayed the same, it will be very usefull to know.

I wonder too if the fan speed changed at all during the 2 tests? Also would it be possible to run it one more time with the black plate off completely?
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
Warning: Attached picture may offend some viewers

Will you post a picture of the feet attached?

Here you are. Initially I placed three feet exactly under the three standoffs however this created some easy tipping when leaning the hand on top to switch the computer on. Also the cables hanging over the edge of the desk were creating some instability. I left the two feet that are in the front exactly over the two standoffs (after all the bottom is only plastic in those locations) and put two feet closest to the corners of the back (has metal backing so less deformity of the bottom cover). (drew with soft pencil a few lines on the aluminium body to locte the studs and the diagonals from the corners). As mentioned before I finally managed to find a spot to affix the MS license label :cool: .
 

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philipma1957

macrumors 603
Apr 13, 2010
6,365
251
Howell, New Jersey
here are my photos. notice the size number these are the lite duty ones best for under 20 pounds.
 

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MJL

macrumors 6502a
Jun 25, 2011
845
1
Non destructive air intake filter

Had some 16 mm thick polyester fibre filter from an air filtration system and cut it to fit underneath the Mac Mini. No more inside cleaning, yeah! :cool:
 

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toss002

Suspended
Jul 16, 2007
149
1
Huntington Beach, CA
Had some 16 mm thick polyester fibre filter from an air filtration system and cut it to fit underneath the Mac Mini. No more inside cleaning, yeah! :cool:

I would do it differently. I'm afraid for your Mac mini. There's not enough air going through the bottom of your Mac mini. It looks like it suffocating. :( (And vacuuming it once and a while isn't that bad.)
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
I would do it differently. I'm afraid for your Mac mini. There's not enough air going through the bottom of your Mac mini. It looks like it suffocating. :( (And vacuuming it once and a while isn't that bad.)

I suspect you are thinking about "normal" foam however you need specialised air filter foam / polyester and the restriction all depends on the PPI (Pores Per Inch) http://www.newenglandfoam.com/filter.html Let me assure you that this is not creating any more drag on the fan, most of the drag is caused by the narrow gap between bottom cover and the aluminium housing.

Proper vacuuming needs almost complete dismanteling to get at all parts and with rapidly worsening arthritis it is something I have to avoid. This air filter only needs the occasional dunking in the kitchen sink.

Besides dismantling voids the warranty.


----------

So what do you guys think of my temps? It this normal?? :confused:

Image

I am used to measure in Celcius and after converting a few they look perfectly healthy, no worries there.
 

smithrb

macrumors newbie
Aug 27, 2011
1
0
Fan "fare"

Forgive the pun, but I'l thinking there's too much fanfare on this subject.

Fancontrol simply solves any issue in my environment. No pads, no elevation, etc...

Installed fancontrol and went from 63 C to 53 C under load.

Next issue...
 

Jamooche

macrumors regular
Jul 23, 2011
204
55
I just installed 4 rubber stick on feet that I got at Home Depot on each corner of the aluminum base to stop the vibration noises that were driving me crazy (sounded like fluorescent lights). Light finger pressure or turning the computer on it's side stops the vibration without the feet. This location also slightly elevates it for better ventilation.
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
Have added some extra ventilation holes in the bottom. Also (as mentioned elsewhere on the forum) it is possible for the i5 and i7 CPU's to turn off the Turbo Boost in Windows 7 by setting in "control panel" - "power options" the "maximum processor state" under Processor power management" to 99%.
( http://tautvidas.com/blog/2011/04/disabling-intel-turbo-boost/ )

No sense in drilling holes in the middle since there the WiFi antenna will be blocking the holes.

I'm doing this in anticipation of buying i7 server and to investigate how much the temperature drop will be.
 

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cocacolakid

macrumors 65816
Dec 18, 2010
1,108
20
Chicago
I got my 2011 Mini Server a few days ago and have been unhappy with how often the fans go nuts. After reading this thread I put a roll of tape under it (first thing I had that was handy and smaller than the base), and now the fans haven't gone off once in the 3-4 hours since, and my CPU temp is 20-40 degrees cooler than it had been all day. I'll look for something a little more attractive than the roll of tape, but hey, it works.
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
I got my 2011 Mini Server a few days ago and have been unhappy with how often the fans go nuts. After reading this thread I put a roll of tape under it (first thing I had that was handy and smaller than the base), and now the fans haven't gone off once in the 3-4 hours since, and my CPU temp is 20-40 degrees cooler than it had been all day. I'll look for something a little more attractive than the roll of tape, but hey, it works.

Good to hear your feedback.

I've bought in the intervening period the 2011 Mac mini with discrete GPU and am running only Windows 7 (OS X removed from HDD). The ventilation holes shown in pic above were 1/8" and they have been enlarged to 11/64". This made no difference in air movement at higher rpm versus the 1/8" holes and did weaken the bottom so placement of rubber feet becomes critical. (far more flex in the bottom in the area above (or below; depending if the machine is upside down or not) the antenna. I even went sofar as using some amplifier heatsinks on the sides (attached with thermal tape) which did keep the enclosure a lot cooler but the internal temperatures were barely affected (2 - 5 degrees C depending on sensor). In the end I took those off again (did not like the look).

I've come to the conclusion that the internal airflow is properly designed and that the enclosure after a long enough time takes on almost the internal temperature.

I am of the opinion that the airgap around the bottom is on the (marginal) small side (OK for the 2010 Mac mini). If this is combined with the computer sitting flat on a desk then one can see that the air gets "pre heated" by the hot enclosure. This has as result that the fan is working harder.

I am using Mac_Fan0_65 to manually set a minimum rpm under windows and when browsing etc have it at 2100. When running unattended with some 10%-15% load I have it set at 2300 rpm (same as the minimum server speed) and it stays pretty comfortable at that level.
 
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