A 45 nanometer production semiconductor "wafer". Next these CPUs will be sliced up as individual chips.
It’s gonna get hot!
Squeeze 410 Million transistors onto a CPU (Central Processing Unit) chip that’s smaller than a dime and you’ve got some serious heat to deal with. Note that the CPUs above are shown laid out on their production “wafer” – before being cut up into individual “chips”. The latest chip fabs (fabrication facilities or chip factories) use the new 45 nanometer production process. In other words, the narrowest “wire” (or other feature) width is 45 billionths of a meter. That’s now they manage their miniaturization miracles.
Nobody’s 100% perfect
That 2nd Law of Thermodynamics (the clause by Mr. Carnot perhaps) says that nothing is perfect when it comes to efficiency. Doing work always makes for some waste and that usually manifests as heat. If Intel’s tiny transistors are even 99% efficient in putting their electricity supply to work, 410 Million of them (crammed elbow-to-elbow) are going to work up quite a 1% sweat – depending on what you and Microsoft are ordering them to do, of course. Intel says these babies are turning on and off 300 Billion times a second – so they don’t get much cooling off time between cycles either.
Thermal Solutions
The bottom line is that the people who design the brains of your computer are in a constant battle against the heat that could make your processor protect itself by slowing down or by shutting down your computer. It could even suffer a fatal heat stroke. It’s called “Thermal Engineering” and it’s about coming up with “Thermal Solutions”. The current consumer computer Thermal Solution is to use a “CPU Cooler (mounted on top of the CPU chip) to coax excess heat out of your CPU and into the metal fins of a “heat sink”, where it gets blown away with fans. Besides the CPU cooler fan, there’s usually one or more fans to pull cooling air into your computer case and maybe even more fans to blow the heated air back out of the case.
Intel CPU Cooler
If wishes were horses…
So far so good – if you have enough fans to blow enough air, if you can stand the fan noise, if you have plenty of cool air available and if you have a good way to exhaust the heated air out the back. …A whole lotta ‘ifs’, right?
Ideal Vs the World
Intel and the other chip makers assume their products will be used under “normal” (read “near ideal”) conditions. Not much different from you assuming you won’t be up all night next Tuesday, felled by the common cold this month, or win the Lotto during your lifetime. They can’t very well assume the worst and stay in business.
You are the weak link
But that means these manufacturers depend on you to not torture their chips. Let’s look at a not-that-unusual torture session, conducted by a computer user who represents that “worst” which Intel didn’t assume.
Intel’s assumptions
Let’s also assume you use an Intel desktop processor on an Intel motherboard. Intel specified that the people who built your computer used Intel’s thermal solution (see drawing above) with their processor. That is, they correctly installed the heat transmitting goo between the CPU chip’s metal case and the “heat spreader”, which transmits that heat to the heat sink, then they properly installed the heat sink itself, with its 51 fins to provide lots of heat dissipating surface area for the cool air from the properly installed Intel CPU cooler fan.
By the way, I don’t mean to pick on Intel – it’s the same for the others. In fact, I like Intel a lot, have had excellent support from them - and I do use their products when I design and specify computers for my clients.
Transistor torture
How does our hapless user inadvertently torture their transistors? For instance:
Their home office doesn’t have air conditioning. Today it’s 94 F degrees outside. So much for supplying cool air to the CPU cooler.
Also, this user bought one of those “computer desks” from a manufacturer that doesn’t know anything about computers. The computer is therefore jammed into this desk compartment which has a solid back, top and sides and no air vent holes drilled anywhere. There is maybe 4″ of space around the computer case. So much for intake airflow or for exhausting the hot air out the back of the computer case. Are you feeling the pain of that CPU chip yet?
But more than the CPU is suffering. Intel’s thermal solution uses the air that leaves the CPU cooler to also cool the voltage regulator chips and some other vital parts which they have arranged around the CPU. What with hot air coming into the computer case and being further heated up by the hot CPU, before flowing over these other components, they are also in a heavy sweat. Excessive heat may be shortening their lives.
Disaster strikes
What happens? Our user comes in, sits at their desk, fires up their email program and downloads a bunch of email. The CPU gets busy with the email and with that anti-virus scanner looking at each message as it comes in, and with the news site the user brought up to pass the time waiting for their mail – and the computer first slows to a crawl, then shuts itself down. Maybe it will start up again after a few minutes of cooling-off time – maybe it will never start again. It can only survive so much torture.
National ‘Be Kind to Your Computer Day’
I guess by now you’ve got the message. If you want your computer to be frisky and enjoy a long and productive life, give it plenty of cool air, plenty of room for airflow around it and plenty of fans. And use it in an air-conditioned space, if possible. Also don’t forget to open it up and clean out all those airflow blocking dust bunnies every couple of months.
Please feel free to comment below…
Until next time, stay cool…
_jim coe
Tags: computer cooling, reliability
