XPS 8950, upgrade to GTX 4090?

All, 

Been following this thread and a couple others on the XPS 8950 1000w power supply and GPU support bracket. I think like some others here, I purchased an XPS 8950 with the minimal GPU (GTX 1650 Super in my case) and the upgraded 1000w PSU with the intent of upgrading the GPU on my own. I am very happy with were I ended up but the process had more nuance and details to learn than I realized. I figured I would consolidate my "notes" here for others to benefit from too.

I ended up buying a Gigabyte Radeon RX 7900 XTX Gaming OC when they were on sale for $900 recently. Though I was mostly considering a RTX 4080 or RTX 4090. Nvidia's cards just not coming down in price and the "fit" challenges detailed below really are what pushed me towards the 7900 XTX. 

The RTX 4080 and 4090 are really large cards, while I never actually tried to physically cram one in there, at the time of writing this I think the only that would fit based on my measurements is the Gigabyte 4090 WINDFORCE V2. "V2" / Version 2 is key as they shrunk the vertical size to less than three slots. However it is still relatively new and priced at $1700 the places I have seen it available at the time of writing this. Maybe the FE would fit with the PSU shroud removed but even if it did fit, I have serious concerns about the remaining clearances for airflow and power adapter dongle situation.

My measurements of the amount of space for a GPU in the XPS 8950:
14in x 6in x 2.25in
355mm x 152mm x 57mm

Note that my system did not come with a plastic shroud / bracket on the front fan (right side of picture below). But I have seen it pictured on other 8950s. If you have it, it probably needs to be taken off to fit any modern, high-end GPU.

Even the Dell 1000w PSU only comes with two 8-pin power connectors. Each with their own 6-pin piggy-backed on the same wires. The RX 7900 XTX has a similar power draw to a 4080/4090 but most 7900 XTX only have two 8-pin connectors which made it a perfect fit in my book. I guess there should be some set of adapters that get the Dell proprietary 1000w PSU to pump enough power into a 12-pin connector on a 4080 / 4090 but that was a problem I was happy to avoid after a lot of stressing over which combination of adaptors mentioned in the above linked Dell community thread I thought would hook it up. Plus the 12-pin connector itself still is apparently getting all the kinks figured out.

The last piece was figuring out a GPU support bracket. My XPS 8950 didn't come with Dell's proprietary support bracket. I am guessing Dell just don't provide it with the smaller cards like the 1650 SUPER. I went back and forth between Dell Tech Support and Sales for days trying to get the Dell GPU support bracket that clicks right in on top of the Power Supply. But like others, I had no luck. They won't even sell it to you. My 7900 XTX actually seems much more stable than I expected, but I still felt better getting a support bracket. My GPU came with it's own support bracket that mounts to an ATX motherboard standard set of screws. We don't have those screws in the XPS 8950, so no luck. However, I purchased this third party one and it seems to work great.