What are the brown things underneath a cpu?

[Maximilian]

http://www.digitalworldtokyo.com/entryimages/2008/01/080130_CPU.jpg

Those things. Theres been progressively more and more of them, smaller and smaller with different types showing up from that picture of what looks like a pentium 4 to the core i7, i7 is littered with them.

What are they and what are they for?

 

[PottedMeat]

They're power decoupling capacitors and are usually placed as close to the device as possible: http://en.wikipedia.org/wiki/Decoupling_capacitor

Like this ( the ones with multiple terminals ): http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P11993CT-ND

and this ( the ones with two terminals ): http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=490-3896-1-ND

 

[Joepublic2]

^^^ better answer ^^^

ceramic caps (don't know anything more specific than that, though)

 

[Maximilian]

They're power decoupling capacitors and are usually placed as close to the device as possible: http://en.wikipedia.org/wiki/Decoupling_capacitor

Like this ( the ones with multiple terminals ): http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P11993CT-ND

and this ( the ones with two terminals ): http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=490-3896-1-ND

Aha awesome, thanks for that :thumbsup:

 

[pm]

What PottedMeat said.

They are used to reduce voltage droop when the CPU power changes over time - for example, the CPU is in a lower power mode and the user fires up something like a video render and the CPU ramps up in terms of power. The CPU's power requirements increase faster than the power supply can deal with them, so there's capacitors close to the CPU to act as a short-term power-supply. There are more and more of them because as voltages are reduced due to silicon process requirements, and as power stays constant, then current goes up and the problem gets worse.

 

[aigomorla]

arent those brown thing boogers??

j/k

pm and potted nailed the answer.

 

[wwswimming]

arent those brown thing boogers??

not gray enough.