Need help picking X399 motherboard for 4 GPU deep learning rig

[Max36]

Hi, I am building a workstation for deep learning, so I will
stack three 2080 RTX Ti cards and one RTX Titan. The case is an
Lian Li PC-O11 Air which supports eatx (and features bottom fans to support the Titan card, which is not available in blower style). GPU power is by far most important for my workload. CPU is generally minor, however I need many PCIe lanes.

I need to complete the expensive gpu configuration asap, so I bought a Threadripper 1920x for now. However, depending on future experiences, an upgrade to a Threadripper 2990WX at some point is something I seriously should take into account (the main workload for deep learning is GPU, however there are CPU tasks for preprocessing the data).

From previous experience, I have a feeling that cutting costs on the motherboard might be a very bad idea: I am leaning towards the Gigabyte X399 Aorus Xtreme, second choice ASRock Fatal1ty X399 Professional Gaming. The “favorite” cheap option would be MSI X399 SLI Plus. Other boards I could get my hands on are Gigabyte X399 Aorus Pro, ASRock X399 Taichi and Gigabyte X399 Designare EX .

Reasons I would lean to the Gigabyte X399 Aorus Xtreme: First, in reviews I see complaints about its power consumption. However, I will throw four serious GPUs against it, so I might actually be pushing
it to its power sweet spot by fully stressing PCIe lanes (if power circuitry is not all CPU purpose designed, I have no idea)? In the PCIe context, I will also use two 1TB Samsung 970 evo plus NVMe SSDSs (any known compatibility issues?)
Second, it’s a second gen board, supposedly more mature?

I would highly appreciate any thoughts, comments, criticism, points to forum/www posts which might be helpful etc.
(especially if I am about to commit an absolute “no-go”).

P.S.
I know RAM is a difficult topic particularly for threadripper. Maybe I can still add this question: if the RAM module is in the motherboard compatibility list, 4 times 16gb DR, >= 2933MHz, <= Cl16, nice brand (e. g. G.skill): am I nevertheless in danger of “crippling” my performance with it
if I go cheap (b-die modules have their price…)?

Thanks

[TheGlenlivet]

I just broke up and sold a X399 Designare with a 1950X, 32GB of 3600 ram, 1600W PSU, and a custom loop on the cpu and 2 of the 4 1080tis. The other 2 were AIO cooled.
I ran it on windows 10 pro or Ubuntu for either Folding at home, mining or Boinc and it worked well.
I had no hardware issues with the motherboard and VRMs were never a problem with the stock set up or under the water block.
If you are going for an x399 I can recommend that board.

[Max36]

Thank you for the recommendation. Unfortunately, when I looked again at the reseller list, it was only still available considerably overpriced. So I went with the Aorus Xtreme.