65nm, 90nm, et cetera - What do they mean for performance?

[Alex_Huck]

Hi, sorry if these are a questions that get asked every other day (I did try google and forums search though)

I have some questions about processor sizes (90nm, 60, 45nm etc)

What do they call it? Lithography, right?

Is the processor size a factor in its performance, does a smaller processor size mean it can fit more components in a smaller area, which will get more work done?

What exactly is at the nanometer scale, the semiconductors?

 

[godman]

okay by skrinking the size of the transistor (180nm,130nm,90nm,65nm e.t.c....) it means you can focus more components in the same space.

so say your useing a pentium 4 processor going from 130nm (northwood die) ------> 90nm (prescott)
northwood = 1MB L2 cache -------> prescott = 2MB L2 cache
prescott had double the l2 cache along with other interesting features like being 64bit (some) and having hyper threading (6xx series)

advances in transistors meant that you could fit more components into the die. and although hyperthreading (HT) was not anything really to do with the shrinking of transistors but you get my point that :
smaller transistors = allows you to have more components in the same space.

and also shrinking transistors should decrease the heat disipation form the cpu, meaning with smaller transistors less heat is outputed, of corse prescott broke the trend and dissipated about (and more) heat than its predesscessor, the northwood. and eventually intel finally came around and gave us a good processor, the core 2 duo, 40% less heat, 40% more performance

 

[godman]

prescott had double the l2 cache along with other interesting features like being 64bit (some) and having hyper threading (6xx series)

oh and i forgot to mention that prescott had theadded feature of being like an oven :lol:




PS: and i forgot to mention look up moore's law
therory:
every 18 months (1 & a half years) the number of transistors in a chip will double.
http://www.intel.com/cd/corporate/techtrends/emea/eng/209727.htm
http://www.intel.com/cd/corporate/techtrends/emea/eng/209729.htm
...at least i think thats right .... :lol:

oh and by makeing the transistors smaller the cpu is cheaper to manufacture, although the capital costs are always fairly high (the technology needed to make these smaller transistor cpus)

 

[Grimmy]

Actually northwood cores came only with 512kb L2 cache. I don't think I ever saw a northwood with more.

Though, I do remember Precotts going to 1-2MB L2 cache. But then I never saw a Prescott less the 1MB.

 

[Newf]

bump

 

[maury73]

What exactly is at the nanometer scale, the semiconductors?

The nm size reported is the channel lenght of the single MOSFET transistor in the chip. Speaking in simple words, it's the width of a single transistor on the chip, so the more you can reduce it's size, the more transistors you can fit in a sigle die, allowing bigger cache sizes and more calculation units on a single chip.
If you want to learn more on semiconductor scaling look here:
http://en.wikipedia.org/wiki/MOSFET
It's not too technical and explain well the CMOS semiconductor technology.

 

[antoant]

Is the processor size a factor in its performance

No it is not. The smaler size process is. The smaller the size of the transistors the faster they can change states and thus you get results faster.

does a smaller processor size mean it can fit more components in a smaller area, which will get more work done?

A smaller process size (not processor) does allow to fit more components in the same or even smaller area than a larger process size. However, the increase in performance (or to be more exact the biggest part of that increase) comes from the fact that smaller transistors can react faster and signals can propogate faster between different parts of the processor.

As far as heat goes, well that is a factor of a group of things one of them being the process size. A smaller process size does not mean that you automaticaly get less heat and a cooler processor. Heck I am sure I can make a Conroe run hotter than a Prescot. (Although I have not and do not plan to try it). However if everything else is equal a smaller process size does yield cooler running parts.

 

[dmacfour]

what sort of increase in performance will we see from 65nm A64 processors? will it better compete with core 2 duo? will the L2 cache be larger?