How come my Lenovo laptop has a fan but my Chromebook doesn't?

Dreamnine

I know it's to cool down the processor and/or the hard drive but both are SDD.

And why do phones not need cooling down when they now have pretty powerful processors. My iPhone, OnePlus 3T and Xperia X Compact barely even get warm when pushing them to the limit.

Sorry if this comes across as a bit newby but I'd really like to know why some computers require a fan but others don't. I find the fan noise a bit distracting.

kwikbreaks

You'd probably find the cpu slowdown to protect it from frying because there was no fan more distracting or the smoke if it didn't slow down even more so.

Whoever designed the things decided whether or not passive cooling was good enough and if it wasn't they fitted the required amount of ventilation by using one or more fans. A designer who specified fans when none were required would soon find themselves out of a job.

Dreamnine

Why do phones not need them? I've heard of some phones getting almost to hot to touch.

were

The cpu and other devices have become more power efficient, work at lower clock frequencies (do less tasks in a second) and lower voltages. In a cpu you are changing the state of 0 to 1 by swinging the voltage from high to low. Greater the voltage difference between high and low, hotter it gets as it consumes more current. On top of this ramp up the operating frequency and even more power is used. This draining and recharging of the cells causes heat, plus the actual electronic circuit frequency causes the chip to stress and heat too. Read that about 98+% of supplied power to computers ends up as heat.

Some of the Chromebooks have a metal back, or metal keyboard 'backing', these act as big heatsinks.

A phone does have a cpu, but compared to a PC it is limited in capacity, and often not as fast, less features, no mechanical hard disk, and the real power guzzler is often the display. Phones often have a sleep mode where they are barely operational, except for the basics, until they are needed.

psychic_teabag

Does your chromebook use an ARM processor ? Your lenovo laptop is probably x86. (Windows tends to be x86 only, though wince did run on arm. chromebook is linux-based which is fairly architecture-neutral.)

ARM processors tend to use less power, by design. Most phones use ARM. (Not sure what iPhone uses.)

AndyPix

What determines this, is the TDP or thermal design power of the processor, desktop processors can have a 55W-220W TDP, so say you want to cool a 95W TDP processor, you need a cooler that can dissipate 95W, otherwise it will overheat.
For laptop TDP is like 10W-45W so they need cooling too but not as beefy as desktop's.
In mobile phone however the TDP is so small that the CPU package itself can properly dissipate the heat, so don't need active cooling. You will see some modern ultrabooks that uses intel core M processors don't need any active cooling either.


Also, some chromebooks do have a fan - It just may be that its so quiet that you cant tell !

Dreamnine

AndyPix wrote: »

What determines this, is the TDP or thermal design power of the processor, desktop processors can have a 55W-220W TDP, so say you want to cool a 95W TDP processor, you need a cooler that can dissipate 95W, otherwise it will overheat.
For laptop TDP is like 10W-45W so they need cooling too but not as beefy as desktop's.
In mobile phone however the TDP is so small that the CPU package itself can properly dissipate the heat, so don't need active cooling. You will see some modern ultrabooks that uses intel core M processors don't need any active cooling either.


Also, some chromebooks do have a fan - It just may be that its so quiet that you cant tell !

Mine definitely doesn't but my previous chromebook which was lesser specs all round did have a quiet fan.

It's strange - I got a good deal on the laptop around January thinking I may need it if something happened to my chromebook; and that is more or less what has occurred (power button on chromebook is failing). I find the fan noise a bit distracting as I haven't used a PC in years.

kwikbreaks

IME laptop fans only cut in from time to time and when doing some cpu intensive task or other; they rarely run constantly. If this is a new laptop it's unlikely that the vents will be blocked yet but it is possible and that will cause the fan to run pretty much constantly. Are you using it on a firm smooth surface or on carpets, cushions, etc.?

Dreamnine

kwikbreaks wrote: »

IME laptop fans only cut in from time to time and when doing some cpu intensive task or other; they rarely run constantly. If this is a new laptop it's unlikely that the vents will be blocked yet but it is possible and that will cause the fan to run pretty much constantly. Are you using it on a firm smooth surface or on carpets, cushions, etc.?

Just on my lap - the fan seems to kick in rather arbitrarily. The laptop has hardly seen any use so I'm sure the vents are fine.

It's a first world problem, but I do prefer silence.

macman

Put a tray or similar under it.

were

Dreamnine wrote: »

Just on my lap - the fan seems to kick in rather arbitrarily. The laptop has hardly seen any use so I'm sure the vents are fine.

The Acer brand about 6 years ago were dogs. Not only were they prone to bad solder joint issues around the cpu and gpu, the heat sinks on the cpu and gpu were borderline (still have my friends one here), and as they got older and the heatsink compound, size, and fan dirt just did not take away enough heat, which either ended up killing the gpu, or expanding and shrinking the bad solder joints. My friends lasted 25 mins before it would hang/cut out.

The answer was a copper wedge (1mm thick copper pad) on the gpu, next stage was re-balling the cpu/gpu, or nastiest was to replace that nvidia gpu chip and heat sink it again properly if it was dead. Acer was not the only brand caught out with that Nvidia screen chip either.