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hojnikb 看全部
2015-11-18 23:36:37
So basically, 1.53Ghz is really just an overclock and its not really designed to be stable at that frequency... Is that right ?

In that case, it would make sense to have all linux distros at 1.2Ghz and an option for 1.53Ghz.
bronco 看全部
2015-11-19 00:12:21
Edited by bronco at 2015-11-19 00:16

quote:

hojnikb replied at 2015-11-18 23:36
1.53Ghz is really just an overclock and its not really designed to be stable at that frequency... Is that right ?

We (or let's better say the linux-sunxi community) do know that Allwinner's press releases where they claim new chips run with "up to ..." are just marketing chitchat. They don't care at all what's written therein since their main market are tablets or Android OTT boxes where customers like the feeling of having as many CPU cores as possible and the highest "up to" numbers written on the packaging. In recent datasheets and user manuals you won't find clockspeeds -- only recommended voltage ranges instead (understandably since it's not possible to give other recommendations due to the 'thermal design' of tablets and OTT boxes being responsible for maximum cpufreq scaling settings)

All we have are remarks like these that are present in some (all?) H3 fex files:

quote:

; extremity_freq(Hz): cpu extremity frequency when run benckmark or demo apk
;                     1536MHz@1500mV with radiator, 1296MHz@1340mV without radiator
; max_freq: cpu maximum frequency, based on Hz, can not be more than 1200MHz

And we have 'hardware reliability tests'. Unless you torture the H3 with real heavy workloads for hours/days and check data integrity it's not safe to exceed Allwinner's recommended maximum values for clockspeeds and voltages. And while you might be able to run your H3 safely with 1296 MHz and 600 MHz DRAM then this might not be true for someone else. We're talking about dirt-cheap SoCs and not expensive x86 CPUs. The last paragraphs are important when we're talking about SBCs: http://linux-sunxi.org/Cpufreq#.22Overclocking.22

When my Orange Pi PC arrives in a few weeks I will give it a try with default settings and since I do not plan to use an annoying fan and want to use the board as long as possible I will then try settings like these out: http://pastebin.com/kfScnPup (based on loboris' great work and just decreasing clockspeeds here and there down to more sane values. And also extending the dvfs table to let the SoC idle at 0.96V instead of 1.3V -- just an assumption that this happens now with only 2 operating points defined in the Orange Pi dvfs tables)
barquerito 看全部
2015-11-19 07:51:55
Edited by barquerito at 2015-11-19 07:59

as I installed ubuntu-mate in my orange-pi-pc,
I cut the mhz above, CPU h3, so that the CPU speed ranged from a minimum of 480 MHz up to the limit set by me, much more conservative than 1.6 GHz, I understood that this lengthened the life of the CPU. and I just hope that the graphics acceleration mali400 a reality.
if not orthodox method, just hope it works.

my /etc/rc.local:

#! / bin / sh -e
# rc.local
echo 1008000> / sys / devices / system / cpu / cpu0 / cpufreq / scaling_max_freq
echo 1008000> / sys / devices / system / cpu / cpu1 / cpufreq / scaling_max_freq
echo 1008000> / sys / devices / system / cpu / cpu2 / cpufreq / scaling_max_freq
echo 1008000> / sys / devices / system / cpu / CPU3 / cpufreq / scaling_max_freq
echo 0> / proc / sys / kernel / hung_task_timeout_secs
dmesg -n 1
exit 0
whitewind 看全部
2015-11-19 12:03:03

quote:

barquerito replied at 2015-11-19 07:51
as I installed ubuntu-mate in my orange-pi-pc,
I cut the mhz above, CPU h3, so that the CPU speed ra ...

As I understand, all cores have the same settings:

code:

  1. readlink /sys/devices/system/cpu/cpu1/cpufreq
  2. ../cpu0/cpufreq

So, my rc.local looks like this:

code:

  1. echo 600000 > /sys/devices/platform/sunxi-ddrfreq/devfreq/sunxi-ddrfreq/userspace/set_freq
  2. echo 1200000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq


barquerito 看全部
2015-11-19 15:00:04
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