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Higher frequency, higher power consumption

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Sputnik

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Why is it when you increase the speed (clock frequency) of an IC or CPU, the power consumption increases as well? Also why is more heat generated?

Sputnik :idea:
 

Because you are charging and discharging the node and device capacitances more frequently.
 

hi,

y is this in the general forum?

well the answer i can think of is.. i remember studyin the relations between power, frequency and power supply voltage as...

P = Vcc ^ 2 * f * C

Vcc => supply voltage
f => operating frequency and
C => power dissipation capacitance..

and the reason being.. every device is made using the basic CMOS or BJT.. taking CMOS for explanations.. the device STATIC power consumption is very less.. but considering the DYNAMIC power consumption(time varying i/p voltage).... there is partial short - circuiting of the device happening.. that is, wen the input voltage is not close to 1 or to 0 then both P MOS AND N MOS (consider a gate for better understanding say nand)... are conducting and so.. there is a current flowing from Vcc to ground...thus power is consumed and this depends on frequency for the reason that... the power dissipates more times as the voltage gets back to the mid state quicker which happens at high frequencies...

hope this explains the problem!

/cedance
 

Thanks, so what would cause damage to a CPU at excessive frequencies, the increased current flow, or the build up of heat?

Sputnik :idea:
 

Sputnik said:
Thanks, so what would cause damage to a CPU at excessive frequencies, the increased current flow, or the build up of heat?

Sputnik :idea:

they are inter related... the excessive or un-necesasry current flow results dissipation of power ultimately leading to heating the components... and damaging...

/cedance
 

So, if the heat can be dissipated fast enough so as to maintain CPU within recommended temperature range, then there's no real danger of damage.

Sputnik :idea:
 

Sputnik said:
So, if the heat can be dissipated fast enough so as to maintain CPU within recommended temperature range, then there's no real danger of damage.

Sputnik :idea:

yeh... that would be the case for all instruments/electrical/electronic items i beleive! ;)

btw, is ur doubt little more than this? if so pls ask what question u intend to ask..

/cedance
 

I overclocked my computer from 3.06GHz to 3.30Ghz and in the BIOS, it says that by overclocking, you reduce cycle-life, but the temperature doesn't change much at all under full load (at night - when cooler).

I'm concerned, as my bedroom becomes quite warm (30 ºC during day), my CPUs temp. doesn't go much higher than about 40 ºC (at idle). But my CPU fan goes from 2700 RPM up to 4000 RPM (and is mighty loud). When I do anything, I'm afraid some damage might occur. I keep nagging my parents for an air conditioner.

One time, I was capturing video in Pinnacle (which sucks) and my CPU, which wasn't overclocked, when upto 60 ºC!

Sputnik :idea:
 

Sputnik said:
I overclocked my computer from 3.06GHz to 3.30Ghz and in the BIOS, it says that by overclocking, you reduce cycle-life, but the temperature doesn't change much at all under full load (at night - when cooler).

I'm concerned, as my bedroom becomes quite warm (30 ºC during day), my CPUs temp. doesn't go much higher than about 40 ºC (at idle). But my CPU fan goes from 2700 RPM up to 4000 RPM (and is mighty loud). When I do anything, I'm afraid some damage might occur. I keep nagging my parents for an air conditioner.

One time, I was capturing video in Pinnacle (which sucks) and my CPU, which wasn't overclocked, when upto 60 ºC!

Sputnik :idea:

i dont think a device level fear should be there for this problem.. i too had the same issues days back.. i changed my SMPS, my old one was a 250 W rated.. now wit a 300 W supply.. and everything is fine now.. i remember my cpu zone 1 temperature shooted to 68 c and zone 3 to 52 degree.... i thought it was under the melting process.. check the power supply ratings in the bios or with the help of software.. incase u are not sure yet.. if it gets below certain acceptable value or greater than then there is definitely some fault and i guess u hav the same problem i had.. and btw, this problem has a symptom of my system getting restarted unusually many times all of a sudden(the one i faced).. do u have same sort of issue?

/cedance
 

Yes, my computer used to (after being sent in for repairs) restart continuously and I was getting so annoyed. I checked in the BIOS and there was this new setting there (the repair meant me having to get a new motherboard - blew my AGP port) (But the really annoying thing is that I sent my computer in for repairs with a Gigabyte 875P motherboard and it comes back with a 865PE motherboard). The setting was "Restart when case opened" and it was disabled and told my case was open, restarting itself unexpectantly. I set it to enabled so that it would restart itself, reset itself and say it is closed and hopefully be the end of my problems and it was, for awhile.

Later I overclocked, but my computer had a cracked version of WinXP (hey, I didn't install it, it was the dude who built my computer). It became unstable, even when not overclocked! My computer began to hang, and then restart every time I used it. I was getting so p... (I wish I had freedom of speech now) that I bought WinXP, formated and reinstalled. All my problems came to an end, my computer runs faster, better and I can overclock now.

Sputnik :idea:
 

hi,

So u are done with ur problems? :) good!

/cedance
 

Yes, I guess I am, but still crashes every now and then. Then again Windows isn't the best, now is it?

Oh, I just want to mention, today, my HDD became 50 ºC. I had a CD image that went corrupt awhile ago, could this be a possible reason.

Very concerned again,
Sputnik :idea:
 

This is an EDA forum and not a PC-overclocking forum!!!
As the description of this subforum says: "Everything else EDA related"

You'll be much better with a PC forum!
 

davorin said:
This is an EDA forum and not a PC-overclocking forum!!!
As the description of this subforum says: "Everything else EDA related"

You'll be much better with a PC forum!

i remember all the answers i made when this post was in the "general section". I have no idea how it moved to the "other design" forum. may be the first question he asked had made moderator to move. but it was really general... i understood that only from the later posts..

/cedance
 

Yeah, why has a moderator moved my thread, WITHOUT NOTICE! I am very dissappointed, I would like to know which moderator moved it.

Sputnik
 

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