Siarhei Siamashka wrote: > > This patch changes defconfigs to have the following set of governors: > 1. 'performance' (default)
[...] > One more reason not to use the 'ondemand' governor by default is > that the power saving provided by it is not particularly good: > > https://www.mail-archive.com/linux-sunxi@googlegroups.com/msg00492.html > <https://www.google.com/url?q=https%3A%2F%2Fwww.mail-archive.com%2Flinux-sunxi%40googlegroups.com%2Fmsg00492.html&sa=D&sntz=1&usg=AFQjCNHjVap33BtE0KfQPxfUzeno8FQGaw> > > > https://www.mail-archive.com/linux-sunxi@googlegroups.com/msg00678.html > http://www.cubieforums.com/index.php/topic,1413.msg8745.html#msg8745 > > It basically wastes a lot of performance for almost nothing. Sorry, I missed the discussion back then (almost 2 years old) and I seem to miss an important piece of information now. The test setups used to measure consumption and drawing conclusions do not mention the dvfs table entries that were used back then. Can these informations found somewhere? Since without it's too early to draw conclusions. I ask because based on experiences with the H3 SoC (Orange Pi PC) I found that the dvfs table's contents can make a real difference regarding performance vs. ondemand/interactive. The Orange Pi's vendor started to 'tune' Allwinner's default settings delivered with the 'SDK' for H3. Just two OPP defined: - 1.53GHz @ 1.5V (already exceeding the recommended max. 1.4V) - 1.2GHz @ 1.3V If I switch on such a system between interactive and performance then consumption (roughly 3 times) and temperatures (over 10°C difference) differ a lot when being idle. The reason seems obvious to me but I might be wrong. With interactive the SoC idles at 1.3V and with performance at 1.5V. I tried to develop a more sane dvfs table with a few more entries [1] which helps a lot with the 'heat problems' the H3 is blamed for (in my opinion Xunlong should be blamed for due to OS images with overvolted/overclocked entries) and it still makes also a difference whether I use interactive or performance regarding idle consumption/temperatures (since with performance the SoC idles at 1.24V and with interactive at 0.98V). So may I ask which dvfs settings were used back then since the assumption that ondemand vs. performance makes no difference regarding idle consumption seem to indicate that identical voltage settings for all cpufreq operating points have been used? Thx, Thomas [1] http://linux-sunxi.org/User_talk:Tkaiser#With_connected_HDMI_display_and_USB_peripherals -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
