Ah, I see what's going on. The Skylake numbers are for a single threaded test. Assuming the A12 ones are as well, what's being said (poorly) is that the single threaded performance of Apple's A12 is better than the single threaded performance of Intel's Skylake Xeon 8176.
Of course there's a different number of cores in each, and the performance of multi-core code will likely differ based on technologies (memory architecture, hyperthreading vs real cores, etc).
If it's accurate, it is still fairly impressive (just not as crazy as it first sounds).
Anandtech is using SpecInt/FP numbers to compare Single core IPC between one A12 BIG core, and one Skylake server CPU core.
Per-core power consumption on that Intel chip is 165/28 = 5.89W.
Apple is pushing similar IPC at 3W instead of 5.89W In that context, it's not so unbelievable, but it's still really fucking impressive.
Of course there's a different number of cores in each, and the performance of multi-core code will likely differ based on technologies (memory architecture, hyperthreading vs real cores, etc).
If it's accurate, it is still fairly impressive (just not as crazy as it first sounds).