iPhone RAM^CPU

[Jet_ski]

I might be in the minority here, but I never knew that iPhone’s RAM goes on top of the CPU. I wonder performance and efficiency they get out of this!

 

(this is from a cool TikTok account.)

 

[Drama Lama]

13 minutes ago, Jet_ski said:

I might be in the minority here, but I never knew that iPhone’s RAM goes on top of the CPU. I wonder performance and efficiency they get out of this!

 

(this is from a cool TikTok account.)

 

Mobile chips don’t output that much heat in mobile it’s often about chip size and the ram is closer to the cpu 

also intel plans „ lakefield“ where the ram is stacked on top of the cpu

[EL02]

59 minutes ago, Drama Lama said:

Mobile chips don’t output that much heat in mobile it’s often about chip size and the ram is closer to the cpu 

also intel plans „ lakefield“ where the ram is stacked on top of the cpu

Side note: They don't output a lot of heat because of thermal throttling.

 

[Zodiark1593]

The configuration is called PoP (Package on Package), and has been common on mobile devices for a long time. I’d read one tidbit that the technique was used as early as the Sony PSP. 
 

For the small PCBs used in modern mobile devices, the space savings are invaluable. 

[Zodiark1593]

3 hours ago, Lord Vile said:

Apple has been using stacked PCBs for ages for space saving.

Not necessarily ages. The original iPhone had a stacked PCB, though it wasn’t until the iPhone X that it came into use again. 

[Jet_ski]

7 hours ago, Lord Vile said:

Apple has been using stacked PCBs for ages for space saving.

Stacked PCBs like motherboards yes. But RAM going on top of CPU specifically, I hadn’t seen.

[Zodiark1593]

13 hours ago, Jet_ski said:

Stacked PCBs like motherboards yes. But RAM going on top of CPU specifically, I hadn’t seen.

If you’ve worked with or studied mobile devices, chances are you’ve seen it a lot.
 

The silicon is shaved quite thin for PoP configurations, and can be difficult to tell apart from traditional packaging unless you specifically look for it.