Zen2 has higher IPC than Coffelake, in stock settings 9900k loses to 3700x in many cases.
At stock clocks and settings - yes I've seen AMD and Intel ST benchmarks go back and forth, depending on the bench - AMD IPC is stronger.
Yet when overclocking, Intel still slightly ahead in single thread performance. Not by much, lol
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Next 36months should see an amazing increase in ST performance from both manufacturers since it's FINALLY a real competition.
Maybe it's only a feeling, but I think these high core counts for processors are going to plateau, and both AMD and Intel will begin to refocus on single and slightly threaded performance which seems to be more difficult.
At stock settings, this ST bench (below) is almost ALL AMD at the top.
Intel 8000 and 9000 CPUs when overclocked can score 100-200-300 some CPUs 400 points higher (on ambient air) on this ST benchmark.
For MT performance, AMD just wins and wins and keeps on winning. lol