On 4/01/2011 12:29 AM, Steven Haigh wrote: > On 4/01/2011 12:08 AM, Adam Williamson wrote: >> On Fri, 2010-12-31 at 08:49 -0600, Richard Shaw wrote: >> >>> I wish I could find the site where I got this information as my >>> recollection of it is a bit hazy but part of your problem may be that >>> the p4-clockmod and ondemand are more or less incompatible. I remember >>> reading something on kerneltrap or something. Basically the latency of >>> changing frequencies are so bad with p4-clockmod that ondemand gives >>> up on it or something like that. I think I could force it to work on >>> my Celeron based EEEPC by manually setting the governor something like >>> this[1]: >> >> yeah, I recall p4-clockmod being called out as problematic in several >> ways by some kernel dev or other, but like you I can't recall the >> details :/ >> >> on my system which wants to use p4-clockmod, I just blacklist it and run >> full steam ahead all the time. > > What I don't understand is that if the CPU supports ACPI, the mainboard > supports ACPI, why can't we throttle the CPU using ACPI? > > From /proc/cpuinfo: > flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca > cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm > constant_tsc pebs bts pni dtes64 monitor ds_cpl cid cx16 xtpr lahf_lm > I think I may have answered my own question: http://ark.intel.com/Product.aspx?id=27512&processor=820&spec-codes=SL88T,SL8CP From this, it states the CPU doesn't support Enhanced SpeedStep or Demand Based Switching - both of which I assume is what acpi-cpufreq uses to reduce power usage on the CPUs which support these features. -- Steven Haigh Email: netwiz@xxxxxxxxx Web: http://www.crc.id.au Phone: (03) 9001 6090 - 0412 935 897 Fax: (03) 8338 0299 -- test mailing list test@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe: https://admin.fedoraproject.org/mailman/listinfo/test
