ha! Do I push or pull?darkbibble wrote:hi I just got a new little 5v 200ma 3.2cfm fan and cut a hole in the lid of my pibow, the thing is do I need it pulling air out of the case, or do I need it pushing air into the case?
I disagree (and especially disagree about the heatsink being enough...if you are in fact referring to an encased Pi3 as there needs to be a way to remove the heat from the heatsink).MarkHaysHarris777 wrote:If the fan is in the top of the case, then evacuate the case by pulling the air out.
...that said, a fan is generally speaking not necessary. If you have heatsinks on the chips that should be enough (I personally hate noisy little fans)
Don't rev up the fan too much, otherwise you'll end up with a Pi-copterRive wrote:I have actually tested this (fan push or pull), and I get better results with push, as demonstrated:
I think he has to register it with the FAA now; as a drone.DirkS wrote:Don't rev up the fan too much, otherwise you'll end up with a Pi-copterRive wrote:I have actually tested this (fan push or pull), and I get better results with push, as demonstrated:
Go BIG, or Go Home, right?MarkHaysHarris777 wrote:I think he has to register it with the FAA now; as a drone.DirkS wrote:Don't rev up the fan too much, otherwise you'll end up with a Pi-copterRive wrote:I have actually tested this (fan push or pull), and I get better results with push, as demonstrated:
Code: Select all
wget https://raw.githubusercontent.com/ssvb/cpuburn-arm/master/cpuburn-a53.S
gcc -o cpuburn-a53 cpuburn-a53.S
while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 10; done& ./cpuburn-a53
Code: Select all
[email protected]:~ $ while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 10; done& ./cpuburn-a53
[1] 1033
frequency(45)=1260132000
temp=36.5'C
frequency(45)=1260002000
temp=53.7'C
frequency(45)=1260000000
temp=58.0'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=65.0'C
frequency(45)=1260000000
temp=68.2'C
frequency(45)=1260000000
temp=70.9'C
frequency(45)=1260000000
temp=73.1'C
frequency(45)=1260000000
temp=75.2'C
frequency(45)=1260000000
temp=77.4'C
frequency(45)=1259998000
temp=79.5'C
frequency(45)=1176000000
temp=80.6'C
frequency(45)=1128002000
temp=81.1'C
frequency(45)=1070998000
temp=81.7'C
frequency(45)=1026000000
temp=81.7'C
frequency(45)=995000000
temp=82.2'C
frequency(45)=958000000
temp=82.7'C
frequency(45)=940000000
temp=82.7'C
frequency(45)=923000000
temp=83.3'C
frequency(45)=880000000
temp=83.3'C
frequency(45)=876000000
temp=83.8'C
frequency(45)=866000000
temp=83.8'C
frequency(45)=852000000
temp=83.3'C
frequency(45)=837000000
temp=83.8'C
frequency(45)=836000000
temp=83.8'C
frequency(45)=835000000
temp=83.8'C
frequency(45)=841000000
temp=83.8'C
frequency(45)=814000000
temp=83.8'C
frequency(45)=842000000
temp=83.8'C
frequency(45)=820000000
temp=83.8'C
frequency(45)=814000000
temp=83.8'C
frequency(45)=817000000
temp=83.8'C
frequency(45)=820000000
temp=84.4'C
frequency(45)=812000000
temp=84.4'C
frequency(45)=809000000
temp=83.8'C
frequency(45)=798000000
temp=83.8'C
frequency(45)=797000000
temp=84.4'C
frequency(45)=789000000
temp=84.4'C
frequency(45)=785000000
temp=83.8'C
frequency(45)=794000000
temp=84.4'C
frequency(45)=800000000
temp=84.4'C
frequency(45)=779000000
temp=84.4'C
frequency(45)=789000000
temp=83.8'C
frequency(45)=770000000
temp=84.4'C
frequency(45)=786000000
temp=84.4'C
frequency(45)=781000000
temp=84.9'C
frequency(45)=774000000
temp=84.4'C
frequency(45)=772000000
temp=84.4'C
frequency(45)=759000000
temp=84.4'C
frequency(45)=774000000
temp=84.4'C
frequency(45)=754000000
temp=84.4'C
frequency(45)=760000000
temp=83.8'C
frequency(45)=756000000
temp=83.8'C
frequency(45)=754000000
temp=84.4'C
frequency(45)=758000000
temp=84.9'C
frequency(45)=749000000
temp=83.8'C
frequency(45)=753000000
temp=84.9'C
frequency(45)=754000000
temp=84.4'C
frequency(45)=750000000
temp=84.4'C
frequency(45)=741000000
temp=83.8'C
frequency(45)=741000000
temp=84.9'C
frequency(45)=747000000
temp=84.9'C
frequency(45)=738000000
temp=84.9'C
frequency(45)=746000000
temp=84.9'C
frequency(45)=755998000
temp=84.9'C
frequency(45)=758000000
temp=84.9'C
frequency(45)=757000000
temp=84.9'C
frequency(45)=761000000
temp=84.9'C
frequency(45)=775000000
temp=84.4'C
frequency(45)=766000000
temp=84.9'C
frequency(45)=761000000
temp=84.4'C
Code: Select all
[email protected]:~ $ while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 10; done& ./cpuburn-a53
[1] 1036
frequency(45)=1260134000
temp=35.4'C
frequency(45)=1260000000
temp=52.1'C
frequency(45)=1260000000
temp=55.3'C
frequency(45)=1260000000
temp=57.5'C
frequency(45)=1260002000
temp=58.0'C
frequency(45)=1260000000
temp=59.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260002000
temp=60.1'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260002000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.8'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1259998000
temp=62.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1259998000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
frequency(45)=1259998000
temp=62.3'C
frequency(45)=1259998000
temp=62.3'C
frequency(45)=1259998000
temp=62.3'C
frequency(45)=1260002000
temp=62.3'C
frequency(45)=1260000000
temp=62.3'C
Code: Select all
[email protected]:~ $ while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 10; done& ./cpuburn-a53
[1] 1054
frequency(45)=1260132000
temp=32.2'C
frequency(45)=1260000000
temp=49.4'C
frequency(45)=1260000000
temp=52.6'C
frequency(45)=1260000000
temp=54.8'C
frequency(45)=1260000000
temp=55.8'C
frequency(45)=1260000000
temp=56.9'C
frequency(45)=1260000000
temp=58.0'C
frequency(45)=1260000000
temp=58.0'C
frequency(45)=1260000000
temp=59.1'C
frequency(45)=1260000000
temp=58.5'C
frequency(45)=1260000000
temp=59.6'C
frequency(45)=1259998000
temp=59.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1259998000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260002000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1259998000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260002000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260002000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260002000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260002000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1259998000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260002000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260002000
temp=61.8'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260002000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.8'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1259998000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260002000
temp=61.2'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=61.2'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.1'C
frequency(45)=1260000000
temp=60.7'C
frequency(45)=1260000000
temp=60.7'C
Keep in mind I meant in general, and I also meant in my own experience. In other words, I can see from your example tests that you have shown a need, and you have shown some evidence; what I'm saying is that in general the system will generally speaking not be loaded that way in most cases and will not require the extreme fan solution you have provided; although, it does look like your setup requires it!Rive wrote:Hmmmm
Well, MarkHaysHarris777 is right, and I stand corrected (well at least on "push" vs "pull" debate), but he is still dead wrong on the "no need for a fan" (with a heatsink and in a case) .
Do you consider floating point calculations normal processing? On a pi3 wouldn't that cause you to overheat & throttle?MarkHaysHarris777 wrote:Keep in mind I meant in general, and I also meant in my own experience. In other words, I can see from your example tests that you have shown a need, and you have shown some evidence; what I'm saying is that in general the system will generally speaking not be loaded that way in most cases and will not require the extreme fan solution you have provided; although, it does look like your setup requires it!Rive wrote:Hmmmm
Well, MarkHaysHarris777 is right, and I stand corrected (well at least on "push" vs "pull" debate), but he is still dead wrong on the "no need for a fan" (with a heatsink and in a case) .
In my own experience small heatsinks (all three main chips) are sufficient to keep the system from throttling while running medium loads normal processing most of the time (normal operations, compiling, number crunching, photo or stream editing, &c). I bought the fan, and its sitting here if I need it, but I have not needed it yet... just saying...
SouceIn computing, floating point is the formulaic representation that approximates a real number so as to support a trade-off between range and precision. A number is, in general, represented approximately to a fixed number of significant digits (the significand) and scaled using an exponent; the base for the scaling is normally two, ten, or sixteen. A number that can be represented exactly is of the following form:
\text{significand} \times \text{base}^\text{exponent},
where significand ∈ Z, base ∈ N, and exponent ∈ Z.
For example:
1.2345 = \underbrace{12345}_\text{significand} \times \underbrace{10}_\text{base}\!\!\!\!\!\!^{\overbrace{-4}^\text{exponent}}
The term floating point refers to the fact that a number's radix point (decimal point, or, more commonly in computers, binary point) can "float"; that is, it can be placed anywhere relative to the significant digits of the number. This position is indicated as the exponent component, and thus the floating-point representation can be thought of as a kind of scientific notation.
A floating-point system can be used to represent, with a fixed number of digits, numbers of different orders of magnitude: e.g. the distance between galaxies or the diameter of an atomic nucleus can be expressed with the same unit of length. The result of this dynamic range is that the numbers that can be represented are not uniformly spaced; the difference between two consecutive representable numbers grows with the chosen scale.[1]
Over the years, a variety of floating-point representations have been used in computers. However, since the 1990s, the most commonly encountered representation is that defined by the IEEE 754 Standard.
The speed of floating-point operations, commonly measured in terms of FLOPS, is an important characteristic of a computer system, especially for applications that involve intensive mathematical calculations.
Code: Select all
sudo apt-get install libmpich-dev
wget http://web.eece.maine.edu/~vweaver/junk/pi3_hpl.tar.gz
tar -xvzf pi3_hpl.tar.gz
chmod +x xhpl
./xhpl
Most tower type cases blow air out of the back, most all power supplies blow air out the back of the power supply and take air in from inside the system. In this configuration, the hotter air should rise to the location of the power supply and be expelled. The cases often have holes or slits in the front in the bottom region of the case. The problem is that there is often a lot more dust closer to the floor than in the air higher up and people who place their systems on the floor tend to see a lot of dust, especially when the case fans or even just the power supply fan run all the time. Essentially they become your round the clock hoover. Once these front slots are clogged, the next place for the air to come in from used to be the floppy disks and then the CD/DVD devices, which contributed to their doom. People who smoke would probably give it up if they looked inside their computer case. Yuk.MarkHaysHarris777 wrote:If the fan is in the top of the case, then evacuate the case by pulling the air out. Why? glad you asked, because you want to minimize the amount of dust in the case, and you want to pull air over the memory chip also. If you pull the air out of the case the new air will come in (mostly) through the hole or slots in the bottom of the case (minimizing dust) and will more evenly cool the entire board.
Yup. Those of us with experience with attic fans know this too... all attic fans pull air in through the house windows and blows it out the top/ and its immediately 'feelable'.stderr wrote:Most tower type cases blow air out of the back, most all power supplies blow air out the back of the power supply and take air in from inside the system.MarkHaysHarris777 wrote:If the fan is in the top of the case, then evacuate the case by pulling the air out. ...
Oh, absolutely. Cigarette smoke filtered through a computer case is the destroyer of worlds...stderr wrote: ... People who smoke would probably give it up if they looked inside their computer case. Yuk.
Yes, usually. My Black Ice cases get warmish; but not hottish... and niether of my PI 3Bs has throttled since installing the three tiny heatsinks. Good 'ol convection is working fine. I should also add, however, that the Black Ice case may be helping out; because, there is a slot in the top of the case over the GPIO pin block (similar to a flew) that allows for 'convection' airflow through the case without a fan. My original idea was to mount the fan in a stiff paper adapter over that slot... so far, it has not been necessary.Netstar wrote:I think that a heat sink is enough to keep the temperature low, if a Pi is in normal use. Because the processor is not calculating at 100% all the time, like in CPU test, it has time to cool down.
My Pi3 is held upright, outside of a case, with all three heatsinks. The heatsinks are the 25C/W ones from ModMyPi. Having it upright, with the fins aligned vertically, gives the best convection cooling. This arrangement is entirely sufficient, and avoids throttling, even for very large jobs.Netstar wrote:I think that a heat sink is enough to keep the temperature low, if a Pi is in normal use. Because the processor is not calculating at 100% all the time, like in CPU test, it has time to cool down.
Dust filters. Dust filters on your intake fans are a life-saver. Pop them off, give them a clean, and you're good to go. Although they won't save a PC from the effects of 20 cigarettes a day being puffed into it .stderr wrote:Most tower type cases blow air out of the back, most all power supplies blow air out the back of the power supply and take air in from inside the system. In this configuration, the hotter air should rise to the location of the power supply and be expelled. The cases often have holes or slits in the front in the bottom region of the case. The problem is that there is often a lot more dust closer to the floor than in the air higher up and people who place their systems on the floor tend to see a lot of dust, especially when the case fans or even just the power supply fan run all the time. Essentially they become your round the clock hoover. Once these front slots are clogged, the next place for the air to come in from used to be the floppy disks and then the CD/DVD devices, which contributed to their doom. People who smoke would probably give it up if they looked inside their computer case. Yuk.MarkHaysHarris777 wrote:If the fan is in the top of the case, then evacuate the case by pulling the air out. Why? glad you asked, because you want to minimize the amount of dust in the case, and you want to pull air over the memory chip also. If you pull the air out of the case the new air will come in (mostly) through the hole or slots in the bottom of the case (minimizing dust) and will more evenly cool the entire board.
That is the same as I have, I haven't even seen heatsinks for elsewhere on the board from the more reputable dealers. I know it isn't strictly needed but I want to make a portable gaming system which of course is going to be in a case with limited airflow so I worry about heat dispersal.darkbibble wrote:I didn't know I'm supposed to have 3 heatsinks, I only got a 6mm high one for the main chip from pimoroni
.
darkbibble wrote:I didn't know I'm supposed to have 3 heatsinks, I only got a 6mm high one for the main chip from pimoroni
.
You are not.darkbibble wrote:I didn't know I'm supposed to have 3 heatsinks, I only got a 6mm high one for the main chip from pimoroni
.