What limits the speed of a computer or cell phone?

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Discussion Overview

The discussion revolves around the factors that limit the speed of computers and cell phones, focusing on the roles of electrical circuits, electromagnetic fields, and the movement of electrons within these devices. Participants explore concepts related to direct current (DC) and alternating current (AC) circuits, as well as the mechanisms of signal processing in processors.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about the drift speed of charges in DC circuits and its implications for the speed of computers and cell phones.
  • Another participant corrects the notion that DC circuits do not generate electromagnetic fields, stating that static fields exist in a perfect DC setup.
  • It is noted that computers and cell phones utilize both AC and DC circuits, with frequent voltage switching in active components being crucial for processing.
  • A participant highlights the importance of microwaves in the operation of cell phones, suggesting that electromagnetic waves play a significant role.
  • Questions are raised about the mechanisms of switching inside processors, specifically whether it is due to electron movement or electromagnetic fields.
  • One response indicates that both electron movement and electromagnetic fields are interconnected, with electrons moving under the influence of electric fields generated by charge density and current flow.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the primary factors limiting speed, and there are competing views regarding the roles of electromagnetic fields and electron movement in the operation of computers and cell phones.

Contextual Notes

Some discussions involve assumptions about the nature of DC and AC circuits, the definitions of electromagnetic fields, and the mechanisms of signal processing that remain unresolved.

Pythagorian
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I am just beginning to educate myself about electricity and computers. Every time I read something I realize my ignorance is even greater than I imagined. For instance, I was stunned to learn that the drift speed of a typical current is so slow.
  • An AC circuit generates an electromagnetic field that travels at a significant fraction of the speed of light. But in a DC circuit no electromagnetic field is generated.
  • A computer or cell phone operates using a DC circuit, and thus does not generate an electromagnetic field.
  • Thus I am led to assume that in a computer or cell phone the speed should be limited by the slow drift speed of charges.
  • But these devices process instructions at a rate of millions, if not billions per second.
So it is clear to me that I am missing some important pieces of information. Please help me to understand or it least point me in the direction that my education needs to go.

Thanks
 
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Pythagorian said:
An AC circuit generates an electromagnetic field that travels at a significant fraction of the speed of light. But in a DC circuit no electromagnetic field is generated.
There is an electromagnetic field, but it is static in a perfect DC setup (nothing changes at all).
Pythagorian said:
A computer or cell phone operates using a DC circuit, and thus does not generate an electromagnetic field.
They use both. Also, the voltage inside the active compoents switches frequently - that is the point of the computer: compute things.
Pythagorian said:
Thus I am led to assume that in a computer or cell phone the speed should be limited by the slow drift speed of charges.
Why should it?
 
One thing you need to bear in mind is that the reason your cell phone works at all is because it is able to receive and transmit microwaves, (EM).
 
Let me try to refine my question.

What is carrying the force that is doing the switching inside a processor? Is it the movement of electrons? Or is it an electromagnetic field?
 
Pythagorian said:
Let me try to refine my question.

What is carrying the force that is doing the switching inside a processor? Is it the movement of electrons? Or is it an electromagnetic field?
Both are related. Electrons move due to an electromagnetic field (mainly due to the electric part), and the electromagnetic field exists due to the charge density (and current flow) that gets influenced by the motion of charge.
 

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