Disappointing Z690/Z790 options

[bambinone]

Hi folks,

I know this is a common topic around these parts but I’m finding the current crop of Z690/Z790 motherboards fairly lacking in expandability. I got a good deal on an i5-13600K and I’m looking for a decent board to pair it with that has a full complement of expansion slots. I’m willing to live with the fact that most of them will be x4 or x1, connected through the PCH, but I would like at least x8-in-x16 and x4-in-x16 slots connected directly to the CPU.

The best candidate so far is the Asus Prime Z690-P and Z790-P, which have the primary Gen5 x16 slot and three Gen3/Gen4 x4-in-x16 slots connected through the PCH. Unfortunately one of the latter is tucked right under the former, rendering it essentially unusable when a two-slot graphics card is installed. And it doesn’t split out its PEG lanes to a second slot.

Anyway, this is more “old man yells at cloud” than anything else, but I thought I’d ask around for suggestions. I know Wendell has mentioned a few boards that have one slot split out from PEG lanes at the bottom (that runs at a slower speed so it doesn’t need a redriver/retimer) but I can’t seem to find them. I have an H670 board that I can use in the meantime until better options hit the street.

Thank you!

• DDR4-3200 4×16GB
• Peripherals
  • Two-slot GPU (Gen4 x16, willing to live with half bandwidth)
  • 10GbE NIC (Gen3 x4, can’t use a built-in e.g. Aquantia NIC due to lack of SR-IOV)
  • SAS HBA (Gen3 x8, willing to live with half bandwidth)
  • [FUTURE] Thunderbolt AIC (Gen3 x4) or built in
  • Renesas USB 3.0 (Gen3 x1) or built in (must support device reset)
  • Second GbE NIC (Gen3 x1) or built in
• Around $200 (lol, I know, but a $500 “creator” motherboard is a non-starter even though it may meet all or most of my requirements)

[jode]

Well argued requirements for an enthusiast setup based.

I have similar requirements for expansion

• 2x Gen4 x16 or 2x Gen4 x8 slots bifurcated for graphics and/or nvme storage
• 1x Gen3 x8 for SAS HBA or Mellanox NIC

There are currently no mobos on AM5 or Intel 13k platforms with these specs. However, I have several AM4 mobos that offer such specs.

I don’t have the budget for a Threadripper-Pro-class workstation setup.

I guess I will have to stay on AM4 for a while longer…

[cowphrase]

Modern motherboards often have heaps of M.2 slots, which you can work to your advantage. You can get intel gigabit chipsets that fit in an M.2 slot (like this). You can also use regular M.2 to PCIe risers in the fancy vertical GPU mounting points that appear in modern cases.

If you find a board that does an 8x-8x split on the GPU lanes, and has a third 4x slot from the chipset, you may be able to run everything else off M.2 risers.

[bambinone]

I’ve definitely considered this strategem if for no other reason than Wendell frequently mentions it in his videos. There’s a Gigabyte Z690 board that bifurcates its PEG lanes into x8/x4/x4, with the x4/x4 going to two M.2 slots, so you could potentially run three expansion cards off the CPU with the appropriate adapters/risers. Unfortunately the cases I currently have and am considering using don’t have any vertical slots. So I could maybe do a gumstick 10GbE NIC if I can find one with SR-IOV support, but I wouldn’t have any place to put a “floating” SAS HBA or Thunderbolt AIC. Not unless I get really creative…