It seems you know the values, based on your claim that N4P is much less efficient that N3. Please provide the details that led you to such claims.
I never said anything about N4P. I said that N4 is 10-15% less efficient than N3. The only real TSMC performance numbers that I have stated come from TSMC press releases. The TSMC charts listed in this thread are from anandtech (main page tech review site) and contain a lot of question marks. They do not know what the performance numbers are. I said it would be nice if TSMC would publish all of their performance differences from one process to another.
Several months about I got attacked for talking about the performance differences between TSMC silicon processes on the same node. People believed all 7nm silicon was the same. All 5nm silicon was the same and that Nvidia hyped up their customized process for PR reasons. Forum members believe that TSMC customizes silicon for their customers and that the process is the same for all. This is not true. N5 is the baseline for 5nm. The first and standard performance. N3 is the first and baseline 3nm process by the same regard. After making thousands of wafers, TSMC perfects each process node. The yields are improved which means each wafer has more chips that are totally functional and not waste. I am not a lithography expert.
Apple has said they were disappointed there was no uplift with N3 (3nm) other than substantial power efficiency gains. The power efficiency gains were offset by Apple increasing the voltage to improve performance going from 5nm silicon to 3nm silicon. When there is a node shrink 7nm>5nm, customers have come to expect an uplift in performance outside of their chip design that comes directly from the fab process. With 5nm, that uplift does not exist like it had with 7nm. With N3 (3nm), there is no uplift in performance according to Apple.
N4P is probably TSMC's way of giving their customers something while they wait for N3P because of the difficulties with 3nm. Nvidia used 4N-something (40 series cards) which is more efficient and better than the standard N4 silicon. N4 silicon is the 5nm variant of what N6 is to the 7nm process. My guess is that N4P is even closer to the standard N3 in efficiency and performance. Probably within 5-7% performance and efficiency compared to N3.
On a side note. Nvidia bought a ton of TSMC silicon that they prepaid for. After the crypto crash and the covid craze ended. TSMC would not refund Nvidia for their huge silicon purchase. My guess is that Nvidia is using N4P (Blackwell) because of all the silicon they purchased from TSMC a few years back. It would seem TSMC gives Nvidia the right to use any silicon they want on the 5nm process node. All you have to do is see how a 4060 sips power. The same can be said of the 4070. Very impressive silicon on the 5nm TSMC process.