But bear in mind we already have board's manufactured for extremely niche use cases which are likely much smaller numbers such as extreme overclocker boards that are not far of 1000USD to buy.
I dont know how board manufacturers find out demand for features (one that I am aware off have a feedback form or feature request form). Their communication with the world is likely only via retailer feedback and the media, and the media is often out of sync with what users might want.
What I do know is I know over 20 people personally who arent happy with PCIe options shrinking, and on top of that 100s of posts read on the internet about similar, so its likely to be much more than a 1000 units required to fulfil demand, I would speculate at least 5 figures. I would expect such boards to comfortably outsell maximus boards e.g. and most definitely APEX boards.
I totally agree with this. I am sure I have heard on of the TechTubers mention that literally 1,000 of some of the overclocking boards are built, so you are certainly correct there.
An ideal for me right now would be:
To move the top M2 slot to the side of the board next to the RAM (as some recent motherboards have done), or much better still, put it on the back of the motherboard but still as close to the CPU as possible for lowest latency.
To actually use the top slot (of 7 potentially available) for the primary x16 slot. (slot 1)
Then 2x slots spaces for M2 drives (empty of PCIe slots), as these are useless for most people with a big GPU (slots 2, 3).
The next two slots to have PCIe 1x slots (slots 4, 5)
The next slot slot to have a physical and electrical x16 slot (slot 6).
And finally another x1 slot (slot 7)
As always with a limited number of PCIe lanes, what slots/M2/SATA can actually be used at once is going to have to be decided by the motherboard manufacturer (there are always some limitations, even on server boards), and the end user.
The second x16 slot would be very useful for someone who wants to use an x16 (4x4) M2 card, an x6 or x16 storage adapter, or a second (thin) graphics card for additional output, with the 1x slots picking up an extra couple of add-in cards. Another option, ( my preferred) would be to swap the last two slots, so the second x16 slot would be at the bottom as many larger cases have an 8th slot anyway, or otherwise breathing room for the 7th slot card.
IMHO, this would fulfil almost all users needs, with the options being limited by the electricals, and the BIOS options. Ideal for many of us who replace an old machine with new, and repurpose the old machine, often with add-in cards as a server, router, video capture etc. This would give all of the options for power-users and gamers, as well as servers, video capture etc.
The last requirement is an absolute MUST, it MUST support Registered ECC RAM.!!! The mid-range and high end AM5 boards from Asrock support registered ECC RAM out of the box, so a perfect "cheap" server or workstation platform.
The graphic is FYI an example of a single slot motherboard with a bit GPU, or a two slot motherboard with only two SATA ports for use as a server or whatever.! This is the AsRock B650 Steel Legend.
Anyway, this doesn't use Slot 1, and the CPU socket has been lowered, so an air cooler would not fit if the actual slot 1 was used. One of the reasons why motherboards like EVGA's often had the RAM at the top and moved all of the power and rotated the socket (Intel platform), obviously workarounds would need to be made.
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A Little example of what can be done with a "server" AM5 motherboard using a B650 chipset and an micro ATX motherboard.!!!
Physical and electrical x4 slot, and x16 slots to the CPU, 1x NVMe to the CPU and a further x1 slot to the chipset. It also includes a remote management chip (has its own graphics, I/O and LAN), 2x Gigabit Ethernet and 2x 10 Gigabit Ethernet.
And of course support Registered ECC.
Also worth noting, because the top slot is an X4 and the placement of the CPU, a big air cooler could be used if the card in the top slot was not too long. This would allow an M2 drive to be used here via an adapter (options.!), and of course it it was ATX there are another 3 slots of potential building on the basic design and layout of this motherboard.
FYI, I have looked at Supermicro and Tyan, they do not have anything to add in their AM5 server/workstation options (currently), although Supermicro has a sick looking 8x AM5 blade server in a 4U chassis, so even the big boys are using the AM5 platform for servers now (supporting Registered ECC was an excellent choice), (Hetzner, (a big German internet services company) has it's own custom AM5 boards, as noted by Der8auer when he wandered around one of their facilities, they also sponsor his channel)), so there are real world examples of AM5 motherboards with all of the features that you could want, if you buy enough of them...
www.asrockrack.com