On 3 July 2013 18:33, Richard Earnshaw <rearn...@arm.com> wrote: > On 03/07/13 17:41, Renato Golin wrote: >> >> On 3 July 2013 17:22, Mans Rullgard <mans.rullg...@linaro.org >> <mailto:mans.rullg...@linaro.org>> wrote: >> >> I repeat, the 4460 will run at 1.2GHz indefinitely without thermal >> management. >> >> >> My mistake, I said 1.3GHz when it was actually 1.2GHz. So, at 1.2GHz, it >> freezes every few hours on full load on both 4430 and 4460. >> >> linaro@linaro-panda-01:~$ cat >> /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq >> 1200000 >> >> Now what? > > > > keep lowering the clock limit (.../cpufreq/scaling_max_freq) until you get > stability. If you don't, then it isn't a heating problem. > > Remember that manufacturers match the form of packaging to the expected TDP > of the intended usage environment (to keep product costs down). In a > mobile part that probably means relatively cheap plastic package because a > hot chip would burn a hole in your pocket -- literally. The package almost > certainly doesn't have a high thermal conductivity from the chip to the > external surface so while a heat sink might help, it won't be as effective > as with other packaging options. > > Chips expected to dissipate large amounts of power normally have a metal pad > on the package so that a heat sink with thermal grease will make a good > thermal contact.
The PoP RAM also complicates cooling. -- Mans Rullgard / mru _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-toolchain
