True. To be more specific, what I was trying to speak to was chipset SATA ports rather than the ASM1061 extensions on Taichis. I haven’t seen perf measurements of the X670E’s ASM1061s but past Taichis using 3.0 x1, an ASM1061, and a multiplier only managed 170-200 MB/s on those four ports. Since the X670E Taichi uses two 3.0 lanes for two ASM1061s hopefully it doesn’t throttle with single actuator hard drives, though dual actuator or SSD pairings remain lane limited. The other four SATA ports are direct from the second Promontory 21 and thus shouldn’t be lane constrained.
The X670 Pro RS is maybe a better candidate here. ASRock could expose all eight chipset ports on an X870E Pro RS by changing out the M2_4 connector. In the meantime, it should be possible to get seven SATA ports (but not eight) with an MSAT2SAT3 or equivalent mSATA to SATA adapter in M2_4. Haven’t seen anybody confirm this, though I might bench it out at some point.
an aside about M.2 host bus adapters
There’s plenty of two port M.2 to SATA implementations using the JMB582, as well as six port ASM1166 implementations, but they’re mechanically fragile, thermally iffy, and if the JMB582 runs like the JMB585 it’s a downgrade from Promontory 21 SATA. The Promontory 21’s SATA ports are fine and I’d like to, y’know, just use rather than having to add a host bus adapter and, in the case of the Pro RS, maybe not be able to get the cables out from under a dGPU or have GPU exhaust overheat the host bus adapter.