@FredeBR It seems you're from Brazil if I'm not mistaken. Last time I visited there, hardware prices seemed very high and a lot of Brazilian enthusiasts are quite innovative in their hardware choices given the pricing constraints. They also tend to trend towards AMD.
Basically all the ASRock AM4 motherboards support ECC (even in their spec sheet). After that ASUS has the second best support, however their top motherboards (Crosshair Hero) doesn't support it for some reason.
Having recently switched to Ryzen for my main computers, I do feel some frustration with the limited PCIe lanes, especially PCIe 3.0. Tbf Intel consumer platforms are also realistically limited since in terms of bandwith the DMI 3.0 link is roughly equivalent to the PCIe 3.0 x4 link AM4 uses for the 3x0/4x0 chipset (3.93 GBps vs 3.94 GBps respectively). That means that although e.g. the Intel Z390 chipset exposes 24x PCIe 3.0 lanes via the chipset, the combined bandwidth is bottle-necked at the DMI 3.0 link which only can pass through the rough equivalent to a x4 link. I suppose that might be a better implementation anyway because of the flexibility compared to the AMD chipsets where you must choose whether you'll place a card in the CPU PCIe 3.0 or chipset PCIe 2.0 slot. It's unlikely a regular user would consistently max out the DMI 3.0 link unless they are doing let's say an extended sequential transfer across multiple NVME drives.
Here's a quick comparison of "real PCIe 3.0 lanes":
- Ryzen - 24x PCIe 3.0 (x16 or x8/x8 GPU + x4 NVME + x4 chipset)
- Threadripper - 64x PCIe 3.0 (x16 GPU + x16 GPU + x4 NVME + x4 chipset + x24 general purpose)
- Coffee Lake - 16x + 4x PCIe 3.0 (x16 or x8/x8 GPU + x4 chipset)
- Skylake-X - 44x + 4x PCIe 3.0 (x16 GPU + x16 GPU + x4 chipset + x16 general purpose)