I’ve been reading through mobo manuals and I think the answer is, no. Everything I’ve seen says that if you use the second PCIe slot you’ll be running at x8/x8.
Does this matter if I go LGA1700 with pcie 5.0?
In the end, I’m trying to run a 3090 (pcie 4.0 x16) and a dual port 25gbe nic (pcie 4.0 x8). I might upgrade that to a 100gbe nic (pcie 4.0 x16).
If i can get away with Z690 or X570, that’s what I want to do. But I’m thinking this isn’t an option and I’m going to go threadripper.
The limitation isn’t with the chipsets but with the CPUs. Neither Alderlake nor Ryzen provide enough PCIe 4.0 lanes to run two cards at x16 along with storage, networking, and USB. You’ll need to go threadripper if this is important to you.
No, it would only help if both your GPU and NIC were PCIe 5.0 devices. Then you could run them in x8 mode with the same effective bandwidth as PCIe 4.0 x16.
I think at this point in time it´s likely a smart idea,
to just wait untill both AMD and Intel release their new HEDT platforms.
Because i think that the current Threadripper platform is also on it’s last legs really.
Of course Threadripper does provide all the pci-e lanes you gonna need.
However the platform itself is kinda starting to show it’s age imo.
Given that pci-e5 and ddr5 and all that good stuff is right around the corner.
Of course if you need a system right now,
then Threadripper is pretty much the best option still. but yeah…
im looking to go X699 myself to replace my TR PRO as a daily driver and more as a server, but id expect X699 (what i assume Intel is calling new HEDT) to have 64 PCIe lanes, due to Xeon W-3300 has 64 and LGA3647 for (Xeon-W) and X299 (Last HEDT) had the same amount of PCIe lanes.
X699 could be all I need, and I’m not in a rush. 48-64 pcie lanes is my sweet spot. the < 32 total lane support is just too light imo. think i’ll do some research and wait and see these upcoming platforms too.
A 3090 will run at maximum performance at PCIe 4.0 x8. It suffers a 3% performance hit at PCIe 3.0 x8.
A 100 GBE single-port NIC will also run at maximum performance at PCIe 4.0 x8. A dual-port NIC will not.