Yes, when the Pi is inside a case like my Pi2 Aukru case, which I linked to a few posts earlier.nooryani84 wrote:Wait.. so even with a heatsink it won't run at 1200 mhz under full load?
Just some numbers for comparison. On a PINE64+ board (quad Cortex-A53 clocked at 1152MHz):Fidelius wrote:Yes, this behavior is new for us Pi users. So far with our Pi1 and Pi2 we never needed to worry about any overheating.nooryani84 wrote:Whats the point with a 1200 Mhz clockspeed if it can only maintain it a few minutes?
So it's indeed a bit disappointing when you intend to use the Pi3 inside a case – you won't be able to have 1200 MHz under full-load then, even with passive cooling (heatsink). When I open the case however, the Pi3 levels out at a few decades below 1200 MHz.
Greetings to Norway!
P.S. Full load meaning something like:
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stress --cpu 4 --timout 600
You mean underclock constantly, I suppose. Then I don't know the answer.Pithagoros wrote:with the increase in heat and associated power waste.
So my question is, can I UNDERclock the Pi3, maybe take it down to 900 or 1000, is there a downside to this apart from a slight performance drop?
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vcgencmd measure_clock arm
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vcgencmd measure_clock core
Thanks for the numbers which are very interesting.ssvb wrote:As we can see, the "minerd" application is roughly twice more power hungry than your "stress" application. And this is a reasonably realistic workload (just one example of a decently NEON optimized code). The users may encounter such workloads in the wild.
The "cpuburn-a53" application is roughly three times more power hungry than the "stress" application and almost six (!) times more power hungry than "sysbench". But admittedly this is just a synthetic workload, which is unlikely to be encountered when running real applications :)
Yes, Cortex-A53 is a true dual issue superscalar with a full width NEON unit. It has 2x faster peak performance per MHz compared to Cortex-A7 (on assembly optimized code) and can easily do heavy number crunching. But the peak power consumption is also higher. Doing something on the GPU at the same time is going to consume even more power.Fidelius wrote: Thanks for the numbers which are very interesting.
So a "minerd" or "cpuburn-a53" combined with some VC4 glbench2 would give interesting temperaturs on a Pi3, I suppose.
The A64 SoC in Pine64 is using the same 40nm manufacturing process as BCM2837 in Raspberry Pi 3, so the power consumption is likely comparable. The Pine64 board also does not have a heatsink out of the box just like Raspberry Pi 3 and throttles almost immediately to something around ~1GHz under heavy load. You would not be better off with a Pine64 board (assuming that RPi3 eventually gains the ability to run 64-bit kernels) because Pine64 is a cost optimized board and this clearly shows. In fact I would probably get a Raspberry Pi 3 board myself if it was available earlier You can find a comparison between the Raspberry Pi 3, ODROID-C2 and Pine A64+ boards here: http://www.cnx-software.com/2016/03/01/ ... comparisonnooryani84 wrote:So how aggressive is the throttling? How much does it scale down to when it reaches the temp limit? I'm wondering if I would have been better off with a Pine64 now
Soft but reliable throttling-back according to my simple tests. I.e. no saw tooth. Looks to be efficient.nooryani84 wrote:So how aggressive is the throttling? How much does it scale down to when it reaches the temp limit?
Thanks. You're probably right on the last part I'm sure that it will perform well, I was just worrying about sudden/dramatic decrease in performance when playing a game or watching a movie. I guess I'm making a mountain out of a molehillRaTTuS wrote:I think there are a few issues here -
one if you run the GPU / CPU cores flat out 24x7 in a case then you probably do
if oyu overclock you probably do
there may be an issue with the on demand cpu scaler not switching correctly
there can and probably will be fixed
http://uk.farnell.com/amec-thermasol/mp ... dp/1892471 < may well be the best bet for heatsinks
but the best advice currently is
if your movies are h264 then without any codecs you can watch with no issues - 256Mb Pi 1 will do thatnooryani84 wrote:...or watching a movie. I guess I'm making a mountain out of a molehill
I'm picking it up today and very excited to see how it performs. Haven't touched anything but the first Pi
Should be OK.nooryani84 wrote:What if I'm streaming H.265? I would hope that this will work fine as well if I have a heatsink.
I suggest that somebody installs Quake 3 Arena on a Pi3B to check this out...nooryani84 wrote:I was just worrying about sudden/dramatic decrease in performance when playing a game...
That would seem to be the best advice.RaTTuS wrote:DON'T PANIC
+1JimmyN wrote:If two people are running stress tests on the RPi and one sees 60C and another sees 85C it doesn't mean anything unless they are both using the same stress test.
This is what Gareth is undertaking here: https://www.reddit.com/r/raspberry_pi/c ... _heat_and/GTR2Fan wrote:+1JimmyN wrote:If two people are running stress tests on the RPi and one sees 60C and another sees 85C it doesn't mean anything unless they are both using the same stress test.