The Western Digital WD Black SN850X 1TB wins in 4 out of 6 comparable specs, with 1 tie. Its biggest advantage is Sequential Read (1204% better).
870 EVO 500GB wins in 1 spec (MSRP: 50% better).
Recommendation
Choose WD Black SN850X 1TB if you want the best overall performance — especially sequential read.
Choose 870 EVO 500GB if msrp matters more to you.
