Question Z790 motherboard with 3 working PCIe 16x slots?

[mac_angel]

I'm wondering if there's a Z790 with three PCIe 16x slots that have at least 8x8x8. I've looked around a lot, but the most I've seen was a mobo with 8x8x4 with the CPU. I know that the chipset has up to 20 PCIe Gen 4 lanes, and up to 8 PCIe Gen 3 lanes, and I know that it all shares the bandwidth with DMI v.4 with the CPU. But is there a motherboard that has a PCIe 16x slot from the chipset that will run at either 16x or even 8x?
The only other that I've seen is the Asus ROG Maximus where it mentions the third slot being a PCIe Gen 4 16x, but then mentions the Hyper m.2 card and 4x, 4x/4x. Would that mean you get the full 16x, unless you put in m.2 SSDs?

 

[Eximo]

Not going to be typical, no. And yes, most of the third x16 slots you find are going to be limited to 4x and share bandwidth with other things in the system.

Consumer platform just isn't intended for that use case.

You should be looking at Sapphire Rapids or Threadripper if you want many high speed expansion cards.

 

[geofelt]

What are you planning to do that needs those slots?

 

[mac_angel]

What are you planning to do that needs those slots?

I run three displays with NVidia Surround. I always thought that you had to have SLI to run multiple cards and get NVidia Surround. Turns out I was wrong, and you can run a card per display, and get them to run in Surround. I do this for gaming, so Xeon CPUs are not a great option. It sucks that Intel never kept up with the HEDT platform. I use to run the X99, and then the X299. I still have a Core i9 10940X, which I'm running at 5.0GHz all core. But the tech difference between the i9 10940X and the i9 11900k, clock for clock is actually quite a bit difference, even with quad channel RAM (not to mention PCIe gen 3 vs gen 4).

 

[Eximo]

HEDT is back. Don't let the Xeon name fool you, the new ones are Alder Lake P-Cores, with overclocking. Somewhat reasonable prices too on the lower end, but motherboard cost is going to be brutal for something like a 12 core.

Not sure if consumer availability is too good yet though, but the launch was back in January.

 

[mac_angel]

HEDT is back. Don't let the Xeon name fool you, the new ones are Alder Lake P-Cores, with overclocking. Somewhat reasonable prices too on the lower end, but motherboard cost is going to be brutal for something like a 12 core.

Not sure if consumer availability is too good yet though, but the launch was back in January.

I've been searching if there are any Xeon's that are overclockable, and I came up blank.

 

[Eximo]

W790 chipset supports overclocking.

Already several overclocking records and the like covered in media. I believe any of the chips ending in X, can overclock.

 

[Eximo]

12 cores for $1000, 16 for $1300, and so on. Motherboards will be pricey, and you do need DDR5 ECC, so the total platform cost is well up there. But the only way to get more than 8P cores, also AVX 512 is back.

 

[mac_angel]

12 cores for $1000, 16 for $1300, and so on. Motherboards will be pricey, and you do need DDR5 ECC, so the total platform cost is well up there. But the only way to get more than 8P cores, also AVX 512 is back.

yea, it's not so much more cores that I'm interested in as more PCIe lanes. And the technology is there, in the Core i9 13XXX series CPUs, and the Z790 chipsets, but no one implements it, even when they build a motherboard that has 3 or more PCIe 16x slots. The Asus ROG Maximus Z790 looks like it might, I'm just not quite sure what they mean about the 3rd slot and the m.2 hypercard. I don't need that many m.2 drives. I get that mainstream consumers don't need to populate three PCIe 16 slots, but even Asus and MSI pro series don't.
Thanks for the info on the Xeon chips. I kinda thought I remember reading something about the newer ones being able to overclock again, but I couldn't find anything when I Googled for it.

 

[Eximo]

Well, the hyper card is intended for the Gen 5 slots and lets you install 4x4 Gen 5 PCIe devices or 2x4 and leaving 8x for your GPU. Also shares bandwidth with the first M.2 slot which is PCie 5.0 as well. Not a big fan of this design choice, though there is little impact running even a 4090 at 8x PCIe 4.0.

The Gen 4 x16 slot is only 4x from what I can tell.