Rest is microarchitecture design choices and integration. Apple designs only Apple in mind and can afford to choose expensive solutions for performance gains. Qualcomm processors are sold for a larger number of customers and they have to compromise.
This is just so off. Look at Geekbench's figures for a 865 Plus, add 35% on top and you are still not close to an A14 and miles away from the M1.
On Geekbench, the top 865 is at 887 for single thread compared to 1585 for the A12. If we add 35% to the 865, the expected 888 score is ~1200, still quite behind the A12.
So Qualcomm didn't even compare the 888 to their latest 865+ CPU: it'll be less than 25%, but how much?
Source: https://www.anandtech.com/show/16271/qualcomm-snapdragon-888...
The 25% number is compared to the 865, not the 865+
The one big core is only 13% faster than the big core on the 865+.
>Compared to the Snapdragon 865+ which clocks in at 3.09GHz, this performance advantage should reduce to only 13%, which is less impressive.
https://www.anandtech.com/show/16271/qualcomm-snapdragon-888...
I just looked up the Snapdragon performance vs Apple A14, and it is within ~10% [1]. I have also compared it to an intel processor, and it also ahead [2].
From a quick search, it looks like Qualcomm is a competitive contender, if we're going to ARM. If true, that would be a pretty exciting new world of ARM PCs :)
[1] https://nanoreview.net/en/soc-compare/qualcomm-snapdragon-86...
[2] https://gadgetversus.com/processor/qualcomm-sm8250-snapdrago....