Why are CPUs getting smaller?

OutcastSpartan7

Honorable
Sep 5, 2012
2
0
10,510
I'm new to system building and all that, but i'm not new to physics, 14nm? they are getting so small that electrical discharge will just jump from part to part, surely they know this... But CPUs are tiny anyway. Just make them bigger for better performance and keep the 22nm sizing.

Hope that made as much sense to you lot as it did in my head.
 
-Lower production costs per unit which allows for relatively low price for consumers.
-Increased production efficiency which also indirectly decreases production costs.
-Decreased power consumption.
-Potentially higher clock frequencies due to lower heat as a result of less power consumption.
-Integration of functions to reduce overall system costs. Examples:
---Memory Controller integrated into the CPU.
---Integrated graphic core. Not everyone needs a discrete graphic card, like office PCs.
 

cuecuemore

Distinguished
Originally they were projecting that the smallest fabrication process they would be able to reach would be 8nm before the phenomenon you described would occur, but lately I've seen talk of 6nm and 4nm designs far out on the horizon.
 

InvalidError

Titan
Moderator
If the silicon semiconductors are made of has an insulation breakdown voltage of 200kV/mm, a 4nm chip would have a ~0.8V breakdown voltage not counting other physics parameters that may increase or lower it.

Another reason to shrink chips is to reduce propagation delays across clock domains and gates. This allows either reaching higher clocks or increasing the amount of combinational logic between clocked registers so more logic can be crammed into fewer pipeline stages.
 

A Bad Day

Distinguished
Nov 25, 2011
2,256
0
19,790


-Increased production efficiency because more processors can be made from one silicon die. Silicon dies take money and time to be refined and polished for transistors to be drawn onto them. The less dies go through the process, the better.


Think of it as an automobile factory in terms of economics of scale. The more cars the factory produces, the less each car cost to make. A factory producing 10,000 cars in an ideal situation will be more efficient than a factory producing 1,000 cars.

In the semiconductor industry case, it's cheaper per processor to produce 1000 processors from each silicon die than 100 processors.
 

InvalidError

Titan
Moderator

One die = one individual IC and one CPU unless the CPU is a multi-chip module.

Dies are cut out of a wafer. Bigger wafer + smaller die = more dies per wafer and a smaller proportion of waste along the wafer edge..