Part 600W PSU & PCIe 3.0 x8 for RTX 3080 Bottleneck(?)

[VN_FieldMarshal]

Hi all,

I'm planning on a FormD T1 Workstation build. After a few months of research, here are the current specs:

X570 I AORUS PRO WIFI (this supports bifurcation)
Ryzen 3 3200G (planning on upgrading to Ryzen 9 5900X)
Gskill TridentZ Royal 32GB 3200MHz CL16
Sabrent NVMe Gen4 1TB
Corsair SF600 Platinum

I'm thinking of buying a RTX 3080 or RX 6800XT when either is in stock. If the math checks out, the SF600 should be enough for a 320W card, a 105W CPU, 30W of dual 15" Monitor, DDC pump, max. 60W peripherals, and, of course, ( ͡° ͜ʖ ͡°) RGB. If not, I'll just take a SF750 when it gets restocked.

However, my main concern is about x16 bifurcation to dual x8 for one of the cards listed above and an additional USB-C 10Gbps w/15W/port hub found here (or similar). There is one splitter (PCIe 3.0) I've been looking at and I'll be using just like the FormD T1 build by fabio. From this article, it - PCIe 3.0 x8 equiv. to PCIe 2.0 x16 - should be a few frames lower compared to PCIe 4.0 x16.

I just want to know if this will bottleneck the RTX 3080/RX 6800XT from other benchmark regarding content creation, and if this allows the hub to function. Although, with an additional PCIe x8, it would also be great to futureproof this build.

Thanks to anyone who replies :>

 

[fboost]

THe PSU might workr, but according to IgorsLab Test of several Nvidia cards and PSUs a 600 W PSU could be overloaded with a 3080 because the card has power spikes longer than 20 ms which could trigger overload protection. All this might be fixed with new drivers. Article in Googlenglish
If you spend this much on a system and you are concerned with performance, why not buy a main board with 4 USB 3.1 ports like the Asus Rog Strix X570-I Gaming with a full 16 lanes for the GPU? (I would recommend Asus main boards anyway)
As for future proofing, the Zen 3 (Ryzen 5000) is the last generation CPU for socket for socket AM4 (maybe there will be a Zen 3+ Ryzen 5000XT), Zen 4 will support DDR5 and require a new socket.
I don't want to troll your system with this post, ITX with bifurcation looks really cool. But to me the combination of bifurcation and a possibly limited PSU seems like a troubleshooting nightmare, but I'm neither an expert nor an extreme crammer. *I* would stay far away if there are alternative solutions. The extra space of a HTPC style case and possible integration into an AV rack is what I'm looking for.