Enough PCIE lanes for multi-gpu plus PCIE NVME drives?

[Cypher-Jackson]

I use this PC for video editing, video AI upscaling, and heating my house in the winter (not even kidding). I'm looking to upgrade but I'm not sure if there will be enough PCIE bandwidth.

A lot of my applications can use multiple GPUs for rendering (like Davinci Resolve), or I use the extra GPU to multi-task with Handbrake, Topaz Video AI, games, etc. 

Current build:

i5 11600K
64 GB DDR4

Gigabyte B560 AORUS PRO AX ATX LGA1200 Motherboard
2 TB M.2-2280 SATA SSD
RTX 3080ti
RTX 3080ti
EVGA Supernova 1300W PSU

Planned build:
i9 14900K
96GB DDR5

Gigabyte Gaming X Motherboard? (4 PCIE gen 4 NVME slots)

RTX 3080ti

RTX 3080ti
one NVME drive, but likely add more later.

The current 14900k has only 20 PCIE lanes maximum, so what happens when I use them all up? What if I have 2 GPUS and 4 NVME drives?

[Kilrah]

16 lanes go to the primary PCIe slot, the other 4 go to an m.2 slot, and all the other slots go through the chipset and share the CPU-chipset bandwidth (PCie4 x8). How/what/how many lanes per device will depend on the mobo.

[tkitch]

you'll need to make sure whatever board you buy has both:

1) Ability to do x8 x8 to two separate PCIE Slots (Bifurcation)

2) Proper spacing to fit two GPUs

[GuiltySpark_]

The planned board appears to be the "Gigabyte Gaming X". If we assume they mean the Gigabyte Z790 Gaming X, there is one CPU attached x16 slot then the other two slots are x4 (at Gen4 and Gen3 respectively) off the chipset. Definitely no x8/x8 going on here.

[Kilrah]

There are very few LGA1700 boards with x8/x8 support on the main CPU x16, but it seems ASRock Z790 Taichi is one.

[Moonzy]

28 minutes ago, tkitch said:

1) Ability to do x8 x8 to two separate PCIE Slots (Bifurcation)

why, exactly? unless OP needs the bandwidth, there's no reason to need both x16 slot to get x8 lanes from the CPU

[tkitch]

13 minutes ago, Moonzy said:

why, exactly? unless OP needs the bandwidth, there's no reason to need both x16 slot to get x8 lanes from the CPU

if he doesn't want the crappy x4 gen 3 slot to nerf the hell out of his second 3080 TI, he wants bifurcation, to get Gen 4 x8 to two different slots.

[BentleyOwen123]

50 minutes ago, Moonzy said:

why, exactly? unless OP needs the bandwidth, there's no reason to need both x16 slot to get x8 lanes from the CPU

not using birurcation will basically make the 2nd 3080 useless

[Fasauceome]

51 minutes ago, Moonzy said:

why, exactly? unless OP needs the bandwidth, there's no reason to need both x16 slot to get x8 lanes from the CPU

Given that the rig is for video editing, I think PCIe bandwidth is going to make a bit more of a difference.

[Cypher-Jackson]

According to the motherboard info page, my bottom GPU is running on a pcie gen 3.0 x1 slot. Yet it still saturates the capacity of my 11600k CPU under many rendering loads. Perhaps the bandwidth is not as important under these workloads?
That gen 3.0 x1 slot has still got to be a bottleneck of some sort. If I upgrade to current platform, I would get a pcie gen 4.0 x4 slot, which is a massive improvement to bandwidth

[Kilrah]

Yeah it entirely depends on the workload. Some won't care at all, some will get murdered. So if you know yours doesn't need much bandwidth no need for crazy stuff. Unless you end up wanting to do something that does mind later...