Thank you for your excellent article. In Figure 3, at a frequency of 3.3 GHz, the normalized power of Intel 4 with 8 Vt is 61% less than Intel 7 (1.75 vs 4.5). The frequency at a nominalized power of 3.75 is 12.3% higher for Intel 4 with 8 Vt compared to Intel 7 (3.65 GHz vs 3.25 GHz). Based on the right side of Figure 3, it looks like Intel 4 is better at reducing power than increasing clock frequency.

On the left side of Figure 3, the improvement for Intel 4 is 40% less power or 21.5% higher frequency. Do you have an intuitive way of understanding why the newer process has a larger power savings but a smaller frequency increase at a high supply voltage compared to a low supply voltage?

Table 2 shows Intel 4 has pairs of metal layers for M5 to M14 with the same pitch, but M1 to M4 don’t follow that pattern. What do you think is the rationale for having a pitch of 50nm for M1 and M3 while the pitch is 45nm for M2 and M4?