Forums - Snapdragon 820 - Capacitive load

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Snapdragon 820 - Capacitive load
alucard
Join Date: 17 May 14
Posts: 1
Posted: Thu, 2016-12-22 03:19

Good day All,

I want to calculate the dynamic power of Big and Little cpus of SnapDragon 820.

I know that the formula is :

Dynamic Power = Capacitive load x Voltage2 x Clock Frequency 

but i need to know the value of "Capacity Load" for both cpus(Big and Little). I suppose it is a fixed value, can you give it to me, please?

 

Thank you and best regards

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ToolsPM
Join Date: 15 Feb 13
Posts: 393
Posted: Thu, 2016-12-22 09:20

I don't have this information. Sorry. 

- Rick

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haldi4803
Join Date: 3 Dec 12
Posts: 19
Posted: Fri, 2017-01-20 14:37

i guess for the correct value you'd need a MDP820 and measure each Rail.

But hey, according to the Power_profiles.xml most Manufacturers don't know this value either ^^

 

http://imgur.com/a/g2K7a

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ToolsPM
Join Date: 15 Feb 13
Posts: 393
Posted: Fri, 2017-01-20 17:03

I share your observation that most Power_profiles.xml value are completely incorrect. 

- Rick

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haldi4803
Join Date: 3 Dec 12
Posts: 19
Posted: Tue, 2017-01-24 16:20

Any idea where we could get/find accurate values?

Except buying a MDP820.

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ToolsPM
Join Date: 15 Feb 13
Posts: 393
Posted: Wed, 2017-01-25 08:58

Sadly no. OEMs and SoC manufacturers like QCOM have all of this data, but they don't share it. It's possible to do software modeling to get per-rail or hardware subsystem power data, but no one has released an app that reports accurate data yet. 

- Rick

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santhoshmini009
Join Date: 5 Feb 19
Posts: 1
Posted: Mon, 2019-03-11 22:05

Hi,

I want to know the Memory,CPU Capacity and How to access Hexagon DSP Core on SnapDragon 820 and also about ARM.

So that I can Differentiate both as SDM 820 has both the Processors.

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