heat and overclock(no its not a duh! thing)

[Jerboy]

I KNOW overclocked processor produced more heat than running it without overclocking, but does overclocked processor produce more heat than a processor running at that speed in spec? (i.e. XP1600+ running at 1600MHz(2000+'s) vs. XP2000+ running at 1600MHz).

Also how can I calculate the actual wattage of my processor short of caloric measurement using metal vessel to sit on top of CPU, thermometer and water?
I heard there are programs out there that will do this, but I don't think I can trust them.

 

[Halogen]

overclocking makes more heat than processors meant to handle that speed

as for the Caloric messurement of heat, why the hell would you want to know that? who cares!
most stuff is measured in Joules anyway (kgm^2/s^2)

Watts lead back to metric units like meters and seconds.

 

[Elledan]

A related question: what exactly causes the heat to be produced in chips?

 

[Shalmanese]

<< I KNOW overclocked processor produced more heat than running it without overclocking, but does overclocked processor produce more heat than a processor running at that speed in spec? (i.e. XP1600+ running at 1600MHz(2000+'s) vs. XP2000+ running at 1600MHz).

Also how can I calculate the actual wattage of my processor short of caloric measurement using metal vessel to sit on top of CPU, thermometer and water?
I heard there are programs out there that will do this, but I don't think I can trust them. >>



depends on what voltage they are running at, they are exactly the same core (provided you have the same stepping) so they should run exactly the same.

As for wattage, AMD provide figures for max wattage for each chip (75 - 80 W for XP2000+ IIRC) but if you want to find the real wattage, I doubt water and themometers are going to do you much good as you would be wanting to look for fluctuations. Maybe a bomb calorimeter

 

[CTho9305]

<< A related question: what exactly causes the heat to be produced in chips? >>


I assume you're asking about modern processors. pm sent me this very informative site...

anyway, most of the heat / power disipation occurs when the processor changes state. when everything is settled in a state, there is very little power usage, but when stuff changes, sometimes multiple transistors will move through a conducting state at the same time, allowing a short circuit from Vcc to GND. That burns a lot of power.

to see an example this, look at the "CMOS inverter demo" on that page. when the input switches (click on "A"), (in reality) the input will spend a small time in the "floating" state in the applet (between 0 and 1), where both transistors conduct, so there is a direct connection from vcc to gnd. this is why higher-speed cmos processors consume more power.

edit: and if you scroll down a little further, it shows an animation of the short-circuit (the power consumption section )

 

[Captain4]

<< A related question: what exactly causes the heat to be produced in chips? >>



I always thought it was the resistance of the material used in the circuits. I thought that was why IBM's ability to bind copper to silicon was such a breakthrough since copper has a lower resistance than aluminum.

 

[J.Zorg]

Overclocking your CPU does´t mean that it produces more heat than an original CPU with the same speed.

AMD Datasheet

It only produces more heat than a stock cpu at the same speed if you increase the voltage...

Here is an sipmle calculation with basic physics everybody should understand..

P=Power
U=Current (CPU Voltage)
R=Resitance of your CPU

P = u^2/R

fo example:
if you have a xp1800+ with a maximum thermal power of 66W
than the thermal power of an 2000+ is 1666/1533*66W= 71W (AMD has 70W on their sheet)
Since the resistance of your CPU is always the same:

u1 = Voltage 1
u2 = Voltage 2

(u1^2)/(U2^2) = P1/P2

(1,85^2)/(1,75^2) = 1,117 = 11,7% increase of heat

that means in total if you clock your cpu from 1533Mhz(xp1800+) to 1666(xp2000+) and increase the Voltage from 1,75V to 1,85 you increase the total heat power by 21,4% wich would be 80W then.
This is only a aproximation but should give you a rough idea with how much heat you will be dealing with.