Lets hope 256GB doesn't mean DDR4-1800 ram speeds. I wonder how much performance is lost going from DDR5-6000 to DDR5-3600? I'm considering 9950x as well but now mobo selection is a PITA because I want to keep my x8 dual optane for speed and capacity. x16+x4 across all the major brands put's a dent in my selection process if I want the GPU to run full bandwidth and x8+x8 leaves no room from 10Gbps NIC when I'm ready in the future to build that network without paying up the wazoo for a MB that has that onboard.
I'm hopeful that 256GB will be able to run at 5200MHz, like the current 192GB kits.
As for the mobos, I did give a look at the local selection, and sadly here in Brazil many models are out of stock, and in general, AM5 has fewer motherboard options that support x8/x8 PCIe compared to AM4.
I found a total of 6 motherboards that support this feature for sale here in Brazil (out of 11 options available worldwide), sorted by estimated prices (yeah, pricing here is awful):
B650 Asus ProArt for $400, the only AM5 B650 mobo that supports x8/x8
x670e Biostar Valkyrie for $540
x670e Asrock Taichi for $800
x670e Asus ProArt for $920
x670e Asrock Taichi Carrara for $940
x670e Asus ROG Crosshair Hero for $960
Among these, the Biostar is a bit questionable and also lacks video output through USB-C, so I’ll rule it out (I need video over USB-C to use with my KVM switch).
The B650 ProArt is a downgrade compared to the B550 version (which I currently have). While the B550 has Thunderbolt 4 (40Gbps), the B650 only has USB-C Gen2 (10Gbps). It would still work for my use case, but it’s a bit disappointing nonetheless.
Of all of them, only the ProArt models (both x670 and B650) support video passthrough from a dGPU to USB-C (with a DP input on the motherboard), while the others seem to only have video out from the iGPU.
Using video through the iGPU would likely still work fine for me, but I guess I’d need to mess with stuff like PRIME to be able to use my dGPU for rendering any games, for the rare cases where I actually do play games.
I’ll probably go with the ProArt B650 since it’s cheaper, and I don’t see any obvious advantages in the other x670e options that justify paying more than double the price. The only extra things the x670e offers are PCIe 5.0 (irrelevant for now) and an additional NVMe slot.
Maybe the B850 series will bring something more interesting, but I doubt the prices will be good.