I’m currently researching Z890 boards for a future build to upgrade my Z390 8600k unraid server.
I’m currently using my cache pool NVMe SSDs on a PCIe card in a x8/x4+x4 bifurcation/lane sharing configuration so that my SSDs go through the CPU.
A must-have for the next board is the same (which with some Z790+ is possible on the motherboard now).
A like-to-have is 2 x16 slots with x8/x8 lane sharing. I may want to have a GPU and HBA in-use at the same time. Neither slot would be populated if I had to upgrade tomorrow; so it’s not likely, but it is possible in the future. I’d like to plan for the possibility if I can.
There are a bunch of boards that seem to meet these specs. The problem is that in researching former Z790 boards that met these specs (Taichi series, MEG Ace), the docs stated that if the 2nd x8 slot was used the 2nd M.2 CPU would be disabled. That’s a deal-breaker if i want to plan for x8/x8.
The docs for the supported Z890 boards don’t state this limitation but leaves me wondering if it still exists and they’re not mentioning it or if the limitation is not there.
Does anybody have one of the following Z890 boards and can confirm or disconfirm if this is the case?
The boards are:
Asus Proart Creator
Gigabyte Aero G
Gigabyte Aero D
ASRock Taichi OCF
MSI MPG Carbon
MSI MEG Ace
MSI MEG Unify-X
Asus Pro WS Ace SE
I don’t fancy spending $400+ on any of these boards, but I’d at least like to know if this path is closed off to me or not.
Thanks
-Tony
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The AMD version of the ProArt at least permits x8/x8, x8/x4/x4, and x4/x4/x4/x4 for the first slot, and x8 or x4/x4 for the second (if the second is used at all the first slot loses the last eight lanes). I would be surprised if the Intel one handles this differently. The other high-end boards probably still have the same functionality. You may be able to find this information in the manual or online, but my experience is that you often need to just buy a bunch of motherboards and try it out for yourself. Use Amazon and just return it if it turns out to be unsuitable.
Note that bifurcation is often referred to as ”NVME RAID” for some godforsaken reason.
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Thanks for prompting me to look at the AMD counterparts to get potentially some more insight
I just read the X670E and X870E user’s and bios manuals for the Creator. They seem to have a reverse generation problem (?) in that the older X670E version doesn’t seem to show a correlating lane limitation between the 2nd M.2 slot and the 2nd PCIe slot, but on the X870E if you populate the 2nd M.2 it pulls its x4 lanes from the 2nd PCIe slot of the x8/x8 lane-sharing config such that you get x4 for the 2nd PCIe slot. I’m guessing it’s because X870E has to sacrifice additional lanes for USB 4 when X670E doesn’t.
That’s not a bad compromise as if i wanted to put a 3.0x8 HBA in the 2nd slot it would be fine and even an older 2.0x8 HBA that would get downgraded to 2.0x4 would be fine for 8xHDDs.
Just to be clear, I mentioned bifurcation, but in an upgrade would just be interested in the x8/x8 inter-slot lane-sharing and not any intra-slot bifurcation (since i’d be moving the M.2s to the motherboard).
While i’m not opposed to going AMD, i need Quicksync and never fancied wasting a PCIe slot on an Arc A310. Not out of the question, but a 9700x+A310 vs a 245K isn’t a wash $ wise either.
Who knows, I upgrade based on needs and not wants so the upgrade may not come for 2 years, when the landscape may change.
I tend to research solutions as I go along just in case a hardware failure forces me into an upgrade.
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The X670E actually does have USB4 even though it wasn’t part of the spec at the time. The difference might be with the chipsets, on the X670E the Thunderbolt controller (Maple Ridge 4C) sits behind one of the chipsets (can’t tell which one, though). I can’t fathom why the X870E model might have used CPU lanes for USB4, but that’s the only explanation that would make sense.
The best way to figure this out is to look at the block diagram for the motherboards; it would appear many vendors no longer provide this for their boards so I would suggest buying from a vendor that still supplies this information.
The Z890-ACE definately would satisfy your needs, you can have two m.2s connected directly to the CPU and still have the two x8 slots active:
You’ll find that Intel offers much more PCIe connectivity this generation than AMD on the consumer platform, this is mainly due to Intel have a much stronger chipset with twice the bandwidth as AMD’s solution.
