Hi, Try this one more time ... On Wed, Jun 29, 2011 at 3:54 AM, Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 2011-06-29 at 12:40 +0400, Dmitry Eremin-Solenikov wrote: > > If you feel like it :-) The powermac one has quite a bit more plumbing > for voltage control etc... but it does make sense in the long run. > On my G5 (PowerMac7,3?), a dual 970FX @ 2.5G, I don't think the voltage scaling works correctly. If someone else with one of these (preferably someone who is NOT swamped (and named Ben)) could run some experiments. I would like to know whether the G5 I bought on ebay is some "FrankenG5" and the others actually work correctly. To summarize, if I disable frequency scaling and look at the cpu core voltages it runs at the LOW voltage at full (i.e. 2.5 GHz) speed. With frequency scaling enabled, it runs the low speed at the same voltage it runs at 2.5 GHz without frequency scaling enabled. At the full speed it switches to a higher voltage. It WILL overheat if allowed to 'do stuff'. Temps above 110 are observed for cpu 1 (the second cpu in the serial (i.e. cpu 1 is heated by cpu 0) cooling setup - DUH!!!). The two voltages are like ~1.23 and ~1.35. Back when this beast had MacOS X, I think it exhibited similar behavior based on the fan noise. kevin -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
