Date: Sat, 17 Jan 2015 14:20:14 -0800 From: Mark Millard <markmi@dsl-only.net> To: Justin Hibbits <chmeeedalf@gmail.com>, Nathan Whitehorn <nwhitehorn@freebsd.org> Cc: FreeBSD PowerPC ML <freebsd-ppc@freebsd.org> Subject: Re: PowerMac G5 quad-core, CPU A1 DIODE TEMP: 90.8 C (for example): How to handle? [Mac OS X behavior] Message-ID: <592299C1-C92D-4CB3-8C4A-DB12FF7D102B@dsl-only.net> In-Reply-To: <4B8426E1-B0C8-430E-BA9F-EBBF2B1B935E@dsl-only.net> References: <42CF1E40-5BD5-4B00-86E9-C62AEB9B8B93@dsl-only.net> <15A6D627-9DC7-48AF-B133-94980AFCE46A@dsl-only.net> <20150115231129.1b28c8d0@zhabar.attlocal.net> <0631235D-A505-4C37-87D7-6F46A14552AB@dsl-only.net> <20150116233145.6708cc6f@zhabar.attlocal.net> <31331F84-63CC-48B7-81B5-E70A22E88CB7@dsl-only.net> <604BAA0A-FD15-4310-88B2-DFEE9988D1EB@dsl-only.net> <20150117080916.3e321a4f@zhabar.attlocal.net> <CAJ-Vmo=0-tzB0U2evzU9XNE6oQU-7_WnqmE%2B9pHWnvRTpkh-Tg@mail.gmail.com> <42358897-0AC2-4B35-BE01-1D4EB2CC2F47@dsl-only.net> <4B8426E1-B0C8-430E-BA9F-EBBF2B1B935E@dsl-only.net>
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I've included a picture of the graph of core temperatures from Mac OS X, = spanning a little over 6 minutes. The core temperature plots are colored = non-black. The "5 to 7" that I mentioned below is more like "3 to 12" over this = time interval. =3D=3D=3D Mark Millard markmi at dsl-only.net On 2015-Jan-17, at 02:04 PM, Mark Millard <markmi at dsl-only.net> = wrote: Mac OS X 10.5 does force idle time of some form to keep core = temperatures down! My evidence is as follows. The application Temperature monitor does show me temperature records = (including graphs over time) under Mac OS X 10.5 for the G5. (No rpms.) = It displays the information as for cpu A 1&2 and cpu B 1&2 (instead of 0 = and 1). A2 is what it shows as a the hot one, matching FreeBSD's a1. I = watched with the current short-term temperature display updating once a = second (set via preferences). Once it reached around the low 90C range on A2 the temperature on A2 = started oscillating, going from the mid/low 90C's down to the = 60C's/70C's and back up again, over and over, fairly rapidly. But the = graph of the temperatures for all the cores shows all the CPU/core = temperatures as oscillating in matching timing. So I conclude that Mac OS X is doing something to give all the = CPUs/cores time to cool down as soon as any one of them gets too hot. So I do not expect Mac OS X to automatically power down, it has already = been far longer than it takes for FreeBSD to shutdown with the patched = RPM/cooling code. Menu meters shows the cores as fully used (mostly = 100%, occasional 99%). They are mostly running 6 of my double/long-long = HINT benchmark variants built various ways with parameter values input = that are designed for long runs. (HINT is memory/CPU limited until it = causes noticeable paging. But I've configured to not page with the 16GB = of RAM avilable.) So far the maximum temperature is 95.8C, and that is on A2. The next = highest core is A1 at 81.2C so far. During this oscillation A2's minumum = is 60.7C so far. There is a pattern to the drops: there is a sequence of 5 to 7 in a row = where the drop starts back up almost immediately but then there is a = longer duration with the temperatures staying down before it starts back = up again. After the longer duration drop the temperature rise is not as = rapid so it is longer until the next forced-drop. For the 5-7 in a row they tend to get somewhat closer together the = further into the sequence. It may be that the time between triggers the = longer cooling duration. The G5 has been kept busy for well over an hour, far longer than FreeBSD = did for "make -j 8 buildworld buildkernel" =3D=3D=3D Mark Millard markmi at dsl-only.net
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