What is something electrical engineers know that others don't?
- The processor in your computer has a billion transistors switching on and off over a billion times per second to bring you Quora today. But you knew that.
- You need special static discharge protection to handle this processor, because the slightest shock from your finger can destroy it. But you knew that too.
- What you probably don't know is how that shock does the deed. Every transistor has an incredibly tiny capacitor (the gate), and the charge separator between the poles is around 10 atoms thick. It's made of one of the most powerful dielectrics known to man, but 10 atoms can only resist a few volts of potential. Most processors now receive an input around 5 volts then down regulate it as low as 1.7 volts.
- That arc you saw on the door knob this morning was well over 1000 volts.
- You can discharge tens or hundreds of volts of static to a conductor without even knowing it. You may not even feel it zap.
- When you touch the lead of a processor without grounding, those hundreds of volts hit the transistors and their puny 10 atom gates like a Mack truck hitting a paper wall.
- Imagine a series of rubber diaphragms designed to work with 5 PSI being hit with a blast of 1000 PSI. It will rip through them as if they're not even there as the pressure desperately searches for a way out.
- But that gate thickness is THE critical variable for processor performance. Every switch of a transistor uses power, which makes heat. The thinner gate lets us cut the voltage, which reduces the heat proportionally.
- Heat is a funny thing in a processor. As a semiconductor heats up, the resistance of a transistor decreases. That's because the energy in the lattice manifests as electrons jumping to the conduction band and becoming available as charge carriers.
- Low resistance should be a good thing right? Sure, when the transistor is on. We EEs have that covered already. But when it's off you want infinite resistance. As electrons become available the transistor begins allowing leak current to pass, and that leak current generates heat.
- You can see where this is going. Past a critical threshold the leak current and heat form a feedback loop. This is called thermal runaway, and the only way to stop it is to shut the system down.
- We can make incredible processors with several orders of magnitude more computing, and we can make them fit in your desktop. But we can't get the heat out. Those silly MEs and their heat transfer are the bottleneck right now. Typical.
- That's also a good summation of the past 50 years and lithography. If we had access to today's mechanical systems and chemical purification 40 years ago, Intel could have made a processor very close to today's in performance. It would have taken a few cycles to get the processing resources to be able to design an i7, but the fundamental principles aren't new. Once again, MEs holding us back. *eye roll*
This is an answer that got collapsed before, so I am writing it again.Warning : Bitter truth that may ruin your fantasies forever.Remember those days in your childhood? When your parents and teachers used to start the day saying :
Most airlines have domiciles in areas which are very expensive to live in. I commuted for 19 years and I hated every minute of it. Flights are always full so either you get crammed in a middle seat or you don't get on as you try to jumpseat only to get bumped off due to seniority.
That is actually a good idea, but ONLY if your pre-workout is NOT calorie dense. Depending on when you had your last meal (evening) your body needs some hours (8-12) to complete the digestion and assimilation of that meal. Only THEN, when the digestive tract is essentially