Entr0py

"intel HEDT motherboards are unique in the fact that they can reassign lanes depending on what PCI-E and M.2 slots are populated. which is not the case with HEDT AMD boards/CPUs. " - that's a big selling point for folks such as myself that need lots of connectivity, and one of the very few reasons I'm not on Team Red right now! However, regarding the specs you provided a link for, the boards listed on there are much newer and designed to accommodate the latest generation of processors. The ROG STRIX X299-E GAMING II for example only hit the shelves a few weeks ago: https://www.overclock3d.net/reviews/cpu_mainboard/asus_rog_strix_x299-e_gaming_ii_review/1 Indeed, x16/x16/x8 will be able to run on Cascade lake (Almost no one should need more than that for 3-way SLI), but the question is whether a legacy x299 board (such as the significantly older 2017 ASUS Prime Deluxe) would now be left over with (48-40 = 8 dedicated CPU PCIe lanes) or (44-40 = 4 dedicated CPU PCIe lanes) which can be utilized by high bandwidth networking/thunderbolt cards etc.

x299 boards have always been marketed as supporting up to 44 PCIe lanes, but the latest i9-10___X series processors have 48 PCIe lanes. It's great that legacy X299 boards now have a BIOS update to support the latest 10th gen processors (BIOS v 2002 for ASUS Prime Deluxe), however no one speaks to whether they will accommodate all 48 lanes... Can the motherboard take advantage of these extra lanes available on the CPU? Or is it hardwired to only support up to 44? Finally, if the extra 4 lanes cannot be utilized, does anyone have the expertise to know if this would affect iommu groupings for something such as unraid? If 4 CPU PCIe lanes are disabled/ignored, this should not cause any issues when carrying out hardware pass-through to virtual machines right? There's already plenty of documentation on manuals indicating the consequences of inserting a lower lane CPU into an X299 board (e.g. 28 or 16-lane CPU) which results in PCIe slots being disabled e.g. m.2/u.2 lane sharing with other physical PCIe slots. I believe the chipset lanes will remained unchanged at 24 or so, and I'm not interested in purchasing an expensive X299X MB, so I feel this information is worth knowing for HEDT enthusiasts!

Did you or anyone else on here follow through with a comparable build in 2019? Since this thread was originally created, a few things have changed, namely some drop in pricing of certain Intel X processors used on X299 MB's, and some adaptaptions need to be made, for example, the USB controller depicted in this video has been discontinued... I personally (and I'm sure many others on here) would be more than happy with just getting a dual VR headset setup on one CPU to work, as VR has become far too anti-social on my opinion. I'm in the middle of buying a new parts list, but as others have mentioned on here, it's difficult to commit to a setup that has been unproven in 2019. Currently, I'm debating going with Core i9 9900K (8 physical cores, 16 logical, for dual VR headsets, 1 cpu) on a modern z390 MB or Core i9-7900X (10 cores, 20 threads) on x299 MB. Both would be paired with RTX 2080 super. The 9900K setup would obviously be the most cost effective, and in theory, should work, e.g. 2 physical + 2 logical cores could be dedicated per VM, or (3P/3L, 6 total) leaving more than enough for the hypervisor. AMD is hard to ignore with 3rd gen 12 cores and up, but I've never seen a proof of concept like this successfully executed on the AMD platform. Thoughts??