Article: Transistor Count: A Flawed Metric
By: Paul A. Clayton (paaronclayton.delete@this.gmail.com), June 2, 2020 7:07 am
Room: Moderated Discussions
David Kanter (dkanter.delete@this.realworldtech.com) on May 18, 2020 7:04 am wrote:
> Dear Friends and Colleagues,
>
> Transistor count and transistor density are often portrayed as technical achievements and milestones.
> Many vendors brag about the complexity of their design, as measured by transistor count.
>
> In reality, transistor count and density varies considerably based on the type of chip and especially the
> type of circuitry within the chip, and there is no standard way of counting. The net result is that transistor
> count and density are only approximate metrics and focusing on those particular numbers risks losing sight
> of the bigger picture. It's not about how many transistors you have, but how you use them.
>
> https://www.realworldtech.com/transistor-count-flawed-metric/
"Effect of Design on Transistor Density" at SemiWiki provides some additional information relative to using standard cells, particularly the greater density achievable by using larger cells (the cells are effectively custom logic and so internally more highly optimized, so internal density will be higher than average density and larger cells will have more internal transistors).
In addition to drive strength density effects, at least before FinFET, low leakage transistors were larger (so a design biased toward low inactive but not power-gated power would tend to have lower transistor density).
> Dear Friends and Colleagues,
>
> Transistor count and transistor density are often portrayed as technical achievements and milestones.
> Many vendors brag about the complexity of their design, as measured by transistor count.
>
> In reality, transistor count and density varies considerably based on the type of chip and especially the
> type of circuitry within the chip, and there is no standard way of counting. The net result is that transistor
> count and density are only approximate metrics and focusing on those particular numbers risks losing sight
> of the bigger picture. It's not about how many transistors you have, but how you use them.
>
> https://www.realworldtech.com/transistor-count-flawed-metric/
"Effect of Design on Transistor Density" at SemiWiki provides some additional information relative to using standard cells, particularly the greater density achievable by using larger cells (the cells are effectively custom logic and so internally more highly optimized, so internal density will be higher than average density and larger cells will have more internal transistors).
In addition to drive strength density effects, at least before FinFET, low leakage transistors were larger (so a design biased toward low inactive but not power-gated power would tend to have lower transistor density).
| Topic | Posted By | Date |
|---|---|---|
| New article: Transistor count: A Flawed Metric | David Kanter | 2020/05/18 07:04 AM |
| Non active transistors | Doug S | 2020/05/18 02:26 PM |
| Non active transistors | Ricardo B | 2020/05/18 09:12 PM |
| Minor quibble about fixed-performance ASIC | Paul A. Clayton | 2020/05/19 03:59 PM |
| Minor quibble about fixed-performance ASIC | David Kanter | 2020/05/21 06:58 AM |
| A complementary article about xtor density | Paul A. Clayton | 2020/06/02 07:07 AM |
| Low leakage transistors | David Kanter | 2020/06/02 07:53 AM |
