Hi there.
Can you tell me how you approached Dell? Did you phone in? Did you talk via support chat, etc.? I'd like to see if I can obtain what I assume are bracket and heat shields for the drives, as I can clearly see the mount holes you mention around the two NVME slots, which are obviously for a dual NVME cooling bracket.
I just (unexpectedly) moved to an Area 51 18 (5090/64gb/2TB) from a very dependable, still great, still warrantied, 2021 Area51m R2.
I wasn't planning on being into the new A51 18 but I am now. I was casually browsing Dell's website last Labor Day weekend and did a simulated config on Dell's website with my personally preferred RTX5080M, 32 GB of RAM, and the basic 2TB system NVME. Plan was to add more RAM later and plug in one of the several good NVME's I have lying about.
This was at the beginning of Labor Day, and that same day, I get an email from my local MicroCenter listing all the Labor Day deals and whatnot. Among those deals was an A51 18 but with a 5090, *64 GB* of ram, and the same single 2TB NVME I had in the build/cart at Dell.
But the MicroCenter 5090 build with/ 64 GB ram was marked down from $4333 to $3100, which was a few hundred less than the build I had at the Dell website, believe it or not. So that kinda gave me a nudge, and so now I'm in it, going through the system migration/setup/etc.
Like you, the first thing I did was pop the back open and install the two 2TB 990Pros I had on the shelf. But, I think my rig was/is the same as yours. All there was on the mainboard were the two empty NVME slots with the obvious NVME insertion slots and the retainer screws, no heatsink, no thermal pads, nothing. So I was kinda like, "wha?" ... instantly trying to figure out how I was going to keep the two 990Pros cooled since those are particularly hot-running drives.
Anyhow, having a bag of tricks in the closet filled with putties, thermal pads, copper shims, kapton tape, etc., I just hacked it with thermal pads on the mainboard thick enough to just support the two extra NVMEs, then put another strip of thermal pads on top of the 990Pros, then stuck about four perfectly sized copper shims onto the top thermal pads and taped everything down with strips of Kapton tape.
It works. I guess. The two 990Pros get up around 65c which is a good bit hotter than I'd like while the stock, Hynix 2TB system NVME stays super chilly and never really goes over 40c. But MAN, I'd certainly have preferred to find some sort of bracket or otherwise that would allow more appropriate NVME cooling shields for the two extra 990Pros.
Thanks in advance for any tips, mang.
~s