freebsd stable - Nov 2016 - Bogus turbo mode with Intel(R) Core(TM)2 Duo CPU P9700 (2.80GHz)

On Fri, 25 Nov 2016 21:16:11 -0700, Jakub Lach wrote:
 > Hello, 

Hi.  Replying to this 'cos your later response to Adrian got .. nobbled.

 > Since I'm running this CPU, I've noticed there is additional
 > field in supported frequency (under heavy load)-
 > 
 > dev.cpu.0.cx_supported: C1/1/1 C2/2/1 C3/3/57
 > dev.cpu.0.freq_levels: 2801/35000 2800/35000 2450/30625 2133/23888
 > 1866/20902 1600/15000 1400/13125 1200/11250 1000/9375 800/12000 700/10500
 > 600/9000 500/7500 400/6000 300/4500 200/3000 100/1500
 > dev.cpu.0.freq: 2801
 > dev.cpu.0.temperature: 67,0C
 > 
 > as far as I know, the +1 MHz mode is a turbo boost factory 
 > overclock, however this CPU does not support it. Anybody knows 
 > what's going on? 
 > 
 > I've previously had T9400 (2.53 GHz), there was no such thing listed 
 > and it was running slightly cooler under load, despite having higher 
 > TDP (however P9700 is a lot cooler when idle, as expected).
 > 
 > Still, I don't think it is possible it's actually being
overclocked?

My X200 has an Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz, less than a 
year older than yours, still Penryn.  Last time I explored this on the 
Intel site it didn't do Turbo Boost as such but it did do some earlier 
version of that; sorry I forget its name or details, and ark.intel.com 
seems different from what I found then.  No time to hunt now.

In a message to freebsd-mobile@ on 4 Feb 2015, in response to mine 
Warner Losh advised:

 > > On my X200 it's '2401/35000 2400/35000 1600/15000
800/12000' and I
 > > found hiadaptive rather aggressive, where adaptive works fine for 
 > > my use - but of course everybody's use is different :)
 > >
 > > powerd_flags="-a adp -b adp -i 70 -r 90"
 >
 > The X+1 number (in this case 2401) is the turbo-mode speed. If you 
 > use X, it disables the Turbo mode which causes the CPU to run faster 
 > until it gets too hot. On my T400, I found that if I limit powerd to 
 > X instead of X+1, I have fewer heat related issues when Im doing 
 > things like building a kernel
 >
 > Warner

So I've run powerd with flag '-M 2400' since without issue either
way.
But then, I'm doing many timing runs where consistent CPU speed at load 
is a virtue, and I recall it definitly ran somewhat cooler at full load.

Not that 67C is particularly hot; running say sysutils/stress with '-c 4 
-t 20m' gets my X200 to >80C in warmer weather, but the fan holds it ok.

cheers, Ian

I've found that the original technology was called Intel Dynamic
Acceleration, 
though it should be only utilized if not all cores working?

I'm ok with overclocking, as you've said, it's not too hot and only
30C when
idle, just wanted to know what exactly is going on under the hood (as in 
frequency, if that's possible) :)



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