What is a Heatsink as Fast As Possible

I get asked all the time "what is a heatsink" and "what does it do?". This video is a little longer than usual but I felt like this topic needed some special TLC.

[BrownJedi]

I love how every time I have a question, Linus shows up with an answer even if it’s from 7 years ago.

[LightningSonic]

Linus, good job explaining what a heatsink is in an easy-to-understand way. I knew most of this already, but I was thinking wrong about what thermal paste does. I just thought it helps to conduct heat better, but didn't think about why it did this. I guess it makes sense that two metals almost never make 100% legit contact evenly.

[anubratakhan]

That moment when Linus says "Speaking and u know it's over... :P

[explosivedude]

*Instructions weren't clear. Cooled CPU to 5 milliKelvin. CPU went quantum and I can't differentiate output 0s and 1s anymore.*

[trippplefive]

ah..the unibrow Linus, we meet again.

[TheHerpieDerpies]

linus is like on every single techchannel on youtube

[andrewweeks]

This just reminds me of a conversation I overheard between a customer and colleague when I was working in best buy many many years ago.... The customer was trying to haggle the price down with the agent, even going so far as to say that if the heatsink was removed, would they be able to lower the cost by a few bucks. It makes me glad that you post these sorts of vids Linus, because sadly there are folks out there that simply don't get it.

[pangeltveit]

So thats why youtubers want us to type comments! They want their videos to be higher up on the searching ranks! Sneaky sneaky! :P

[EmmaCross]

Could you do an AFAP about power, more specifically voltage and watts? You seem to know a bit about that.

[BrickTamlandOfficial]

a heatsink is a piece of metal. the end

[Johhnyp]

Why even bother buying heatsinks, just place ice cubes on the cpu and your good to go.

[rehanchougle]

Linus u have made understanding tech so simple :)

[WolvenSpectre]

Three things you might want to add
1)You mention speed of airflow without mentioning volume of airflow and how faster active cooling doesn't always equal faster cooling airflow
2)The blocking of cooling surface from dust et al lowers cooling and if it gets bad enough actually acts as an insulator to heat up what is being cooled.
3)I think you should touch on Water Cooling/Remote Heatsinks since they are becoming so common with the sealed units.

[SupahCebrailShow]

About those materials.

I'm not a genius, just got this info from my friends, so please take this with a grain of salt.

Copper is great at conducting heat, but not great at removing heat from itself. (i.e: cooling down)
Aluminium is more or less the opposite, being worse at conducting heat, but very good at removing heat from itself.

This is the reason why heatpipes are copper, they are there to remove heat from the nearby component, but after the heat is removed from said component, there's not a big rush to move the heat to the attached heatsink, which is aluminium because it can move heat to the surrounding air much faster.

[truelazerlight]

You forgot a very important way of improving a heat sink's performance: keeping it dust-free.

[joeking]

I love your "as fast as possible" segments.I cant tell you how helpful they have been!Keep up the excellent work!

[thejinchoi]

I just learned about heat sinks in my engineering class a few weeks ago! Thanks for this educational video Linus!

[dacasman]

Surprised he didn't talk about liquid cooling. but I guess that's not a "heatsink" 

[PedroCancel]

I like the fact that you went thru each type of heatsink and what to be aware of very informative thank you

[zackpinkman]

Question: Should fan suck hot air from the heatsink or blow cold air into a heat sink?