what does a cpu's "nm" mean?

[oldtimertoo]

I want to upgrade my cpu from d820 w/95nm to d945 w/65 nm. What does "nm" mean and does the difference affect the interchangeability of the 2 chips? thanks for any info you have.

 

[ingtar33]

nm is "nanometers" referring to the "gage" of the copper in the transistors. smaller numbers mean more transistors can be squeezed into a cpu which generally translates into a faster cpu.

 

[k1114]

It's not related to compatibility. If you really are wanting to upgrade, you are likely to see no difference between those 2.

 

[shuvool]

The D820 was one of the Pentium D processors, and that series was made on a 90nm process. nm is nanometers, or one one-billionth of one meter in length. This is the width of the gates. A transistor at its most basic is a series of P and N gates that allow or restrict current based on bias, and the design process size (measured in nanometers in the last 10 or so years, microns before that) is simply the width of those gates

 

[shuvool]

nm is "nanometers" referring to the "gage" of the copper in the transistors. smaller numbers mean more transistors can be squeezed into a cpu which generally translates into a faster cpu.

Wiring is different. The design process size refers to gates, not wiring, which is sometimes more narrow than gate width. Example: On a 32 nm flash process, your copper interconnects could be 27 nm

 

[ingtar33]

nm is "nanometers" referring to the "gage" of the copper in the transistors. smaller numbers mean more transistors can be squeezed into a cpu which generally translates into a faster cpu.

Wiring is different. The design process size refers to gates, not wiring, which is sometimes more narrow than gate width. Example: On a 32 nm flash process, your copper interconnects could be 27 nm

i stand corrected.

 

[k1114]

It actually refers to the half-pitch.

 

[shuvool]

It actually refers to the half-pitch.

In memory, yes. Logic uses gate length