Turboboosted Turboboost?

sedrosken

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Conky on my Debian install reports my turbo-boosted clockspeed, Ubuntu doesn't. Also, my turboboosted clock speed on Debian is 2900 MHz. Normally it maxes out at 2400. How is this possible? Is it even possible? Is Conky lying to me? Under Ubuntu, Conky would always report my clockspeed when maxing out CPU usage as 2159 MHz, and under Debian when it's maxing out it's at 2900.
 

sedrosken

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What's pretty cool is that it's the FAHClient that's maxing out my cores. I only have one slot assigned, and it's using both cores to their maximum (which is apparently 2900 MHz).

FAHClient seems a lot smarter about using my CPU when set to full under Debian than under Ubuntu. I can use most everything else on my system without slowdown.

Attaching a screenshot of my desktop with Conky, as I can't just snip that part out (I don't have an image editor yet):

2014-10-13-095248_1366x768_scrot.png
 

Chewy509

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Is Conky lying to me?
I would guess,. something is lying...

According to Intel, the max turboboost for your processor is 2.4GHz, up from the normal 2.16GHz...

http://ark.intel.com/products/81071/Intel-Celeron-Processor-N2830-1M-Cache-up-to-2_41-GHz

To see what is really going on, from the terminal run:
Code:
$ cat /proc/cpuinfo
And this will display the current MHz the CPU is running at. eg for my work box, it's:
Code:
$ cat /proc/cpuinfo 
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 60
model name	: Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
stepping	: 3
microcode	: 0x7
cpu MHz		: 800.000
cache size	: 8192 KB

Additionally, the /sys filesystem exports some information as well:
Code:
$ cd /sys/devices/system/cpu/cpu0/cpufreq
/sys/devices/system/cpu/cpu0/cpufreq$ sudo cat cpuinfo_cur_freq 
800000
/sys/devices/system/cpu/cpu0/cpufreq$ cat cpuinfo_max_freq 
3401000
(Numbers are in KHz). So according to the kernel, my current cpu clock is 800MHz, and can be set upto 3401MHz.
Note: 3401MHz is a trigger to allow turbo boost, as if you:
Code:
$ cat scaling_available_frequencies
3401000 3400000 3200000 3000000 2800000 2700000 2500000 2300000 2100000 1900000 1700000 1500000 1400000 1200000 1000000 800000
You'll see two entries for 3.4GHz... One for turbo boost and one for setting 3.4GHz.

More info about Debian and cpu scaling can be found here: https://wiki.debian.org/HowTo/CpuFrequencyScaling
 

sedrosken

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It must be, because under Ubuntu it says my minimum frequency is 498 MHz, and it reports that under Debian as 600 MHz.

And "cat /proc/cpuinfo" returns a bunch of stuff, but I found the line 'cpu MHz' and under heavy load it goes up to 2900 MHz, so either the system itself is lying or Intel is. Or, is it possible that Debian is pushing the CPU past its normal Turbo Boost limit? Ubuntu doesn't seem to be aware of Turbo Boost period, so it's surprising that Debian has such capability.
 

sedrosken

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Didn't edit fast enough.

'cat scaling_available_frequencies', even when in /sys/devices/system/cpu/cpu0/cpufreq, returns a "No such file or directory" from cat.

'cat cpuinfo_cur_freq' returns, under no load, "600031". 'cat cpuinfo_max_freq' returns "2900000". Whatever, as long as nothing breaks and my fans still put out cool air, I'm happy. Just thought I'd share that with you guys, kind of a shared "what in the world is going on here" kind of moment. Are there any long-term consequences for it not returning the actual frequency?
 
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