@bad 1% FPS lows?,
It seems you're correct. There is now further evidence proving this by Hubwood's YouTube channel here:
youtube.com/watch?v=ye1k52VTJ9A#
A couple of points:
a) arc b390 seems to be taking double the system ram in almost every game test compared to 890m.
b) most of the time at 17 watt, the arc b390 is not any faster, some cases even slower than 890m. At 35 watt, the intel chip does take the lead, but that's halo wattage. It'll be interesting to see how halo compares as that's what his upcoming video will be on (arc b390 vs 8060s - low tdp testing).
c) bad frametimes and 1% lows in baldurs gate 3, diablo 4 and far cry 6.
And in many games even when the difference isn't so big (assassin's creed, cyberpunk, last of us part 2, Witcher 3), AMD still shows a superior advantage. This is not a good showing considering it is Intel's latest vs 1 year old 890m.
TL;DR - it seems overall from this test that z2 extreme is superior still (in pricing) or equal at 17w (in performance) at the very least to 12 Xe3 PTL. For some odd reason, Intel's drivers are causing games to use a lot more system ram. Wait for next video to see interesting low tdp comparison with halo 8060s.