I'm planning a compact gaming PC in a black Lian Li DAN Cases A4-H2O with these parts: Ryzen 7 9800X3D, ASUS ROG Strix B850-I Gaming WiFi, RTX 5090 Founders Edition, 32GB DDR5-6000, Corsair Nautilus 240mm liquid cooler, 4TB Corsair MP600 Elite NVMe SSD, and a 1000W Corsair SF modular power supply. The total price is about €7,100 (roughly $8,300). I mainly want the best gaming performance possible, especially for 4K high-refresh gaming. Is the 5090 worth its premium over the 5080? Will temperatures, cable routing, and noise be manageable in an 11-liter case? Should I choose 32GB or 64GB of RAM, is one 4TB SSD enough, and does the overall price and parts selection make sense?
4 Answers
The build should work, but cooling and noise will be challenging. An RTX 5090 can produce a lot of heat in an 11-liter case, and its fans will probably be the loudest part of the system during demanding gaming. Double-check Founders Edition clearance and power-cable routing, and use high-quality, quiet case fans. A larger case would give you much better thermal and acoustic headroom.
32GB is still the normal sweet spot for gaming, and most games do not need more. Choose 64GB if you also do heavy video editing, 3D work, virtual machines, or unusually heavy multitasking. Sixteen gigabytes would be hard to justify in a premium build like this.
A single 4TB NVMe SSD is perfectly reasonable and the MP600 Elite is a suitable fast drive. You can always add another M.2 drive later if needed, so storage capacity is mostly about your own game library and workload. The €7,100 total sounds extremely high, though; even with small-form-factor and flagship-GPU premiums, I would compare several vendors and reconsider whether the 5090 is delivering enough value. Also remember that the 1000W supply leaves less margin than a larger desktop system, so verify the GPU's recommended power requirements and connector setup.
For gaming, the RTX 5090 is roughly 50% faster than the 5080, but the price-to-performance ratio is much worse. It only makes sense if you specifically want uncompromised 4K high-refresh performance or also plan to use the system for demanding rendering or compute work. Otherwise, the 5080 is the more sensible choice.
That performance difference is bigger than I expected, so I'll have to decide whether the premium is worth it for my display and games.

If the goal is simply gaming, putting the savings from a 5090 toward a 5080, 64GB of RAM, or a larger and quieter case would probably result in a more balanced system.