This is not what the Taichi manuals say. The OP image is broken and the formatting mangled but what’s quoted is the fine print on the X870E Taichi Lite and Taichi product pages. It could be worded better but, no, ASRock does not somehow increase the Zen 4 and Zen 5 desktop IO die from 28 PCIe lanes to 36 or 44. As @MazeFrame mentioned, refer to the block diagrams in the manuals to see how the 16 PEG lanes are switched from x16/x0 to x8/x8 bifurcation.
Crossfire, I dunno.
I think there’s confusion about how x16 bifurcation works and perhaps some lack of accounting for M.2s and USB 4 on the desktop IO die’s other eight lanes. All X870E boards offer the choice to use all 16 PEG lanes for a dGPU (that I’m aware of, but maybe there’s a weird one). Tabling out boards’ PCIe lane configurations in your build spreadsheet by expanding the below to include chipset lanes may be helpful.
| mobo | PEG | CPU M.2 | CPU USB 4 |
|---|---|---|---|
| Asus Crosshair X870E | x16, x8/x8, x8/M.2/M.2 | 5.0 x4 | very likely ASM4242 |
| Asus ProArt X870E Creator | x16, x8/x8, x8/x4/M.2 | 5.0 x4 | very likely ASM4242 |
| Asus Strix X870E-E Gaming | x16 | 5.0 x4 | probably ASM424 |
| ASRock X870E Taichi | x16, x8/x8 | 5.0 x4 | ASM4242 |
| ASRock X870E Taichi Lite | x16, x8/x8 | 5.0 x4 | ASM4242 |
| ASRock X870E Nova | x16 | 5.0 x4 | ASM4242 |
| Gigabyte X870E Aorus Master | x16, x8/M.2/M.2 | 5.0 x4 | ASM4242 |
| Gigabyte X870E Aorus Elite | x16, x8/M.2/M.2 | 5.0 x4 | ASM4242 |
| Gigabyte X870E Aorus Pro (Ice) | x16, x8/M.2/M.2 | 5.0 x4 | ASM4242 |
| MSI X870E Godlike | x16, x8/x8 | 5.0 x4 | probably ASM4242 |
| MSI X870E Carbon | x16, x8/x4/M.2 | 5.0 x4 | very likely ASM4242 |
Bifurcating x16 to x8/x8 is for dual GPU as seems to have been noted. x8/x4/x4’s usually to add two M.2s, though the Carbon brings out one x4 to a slot instead. Gigabyte, like ASRock, does block diagrams. So their manuals may also be helpful here. Asus and MSI don’t show their lane allocations, at least in the manuals I’ve checked.
Because they’re the only one of the big four not to offer an X870E board with x8/x4/x4 bifurcation.
Also, once the chipsets are tabled in to be able to fully compare boards on an M.2 basis, I’m pretty sure what you’ll find is the x2s are chipset lane reallocations. In particular, it’s common to bifurcate a Promontory 21’s 3.0 x4 port from x4 NVMe to x2 NVMe/x1 SATA/x1 SATA.