My ASUS ROG Strix RTX 4090 developed a vapor-chamber failure after about nine months in warranty service. ASUS and the retailer acknowledged it as a manufacturing defect, but the 4090 is no longer available. A consumer arbitration ruling requires a defect-free equivalent replacement, and ASUS is offering either a refund of my original 2024 purchase price or one of three 16GB RTX 5080 models: the ProArt RTX 5080, TUF RTX 5080 Gaming, or Prime RTX 5080.
The refund is 92,000 Turkish lira, which has lost a great deal of purchasing power since 2024. A new RTX 5080 costs roughly the same amount today, while a used RTX 4090 costs around 200,000–215,000 lira and an RTX 5090 costs approximately 300,000–330,000 lira.
I use the GPU for local AI models, CUDA work, and rendering, so VRAM capacity matters as much as raw speed. The 4090 has 24GB, while the 5080 has 16GB, and the 4090 appears to be faster for both compute and many workloads. Is the 5080 genuinely equivalent in any meaningful sense, or would it be a significant downgrade for my use case? Should I accept the 5080, take the refund, or continue pushing for a card with at least 24GB of VRAM?
4 Answers
For local AI, 16GB versus 24GB is a major difference, not a minor specification change. Some models that fit on a 4090 will not fit on a 5080 without reducing the model, offloading layers, or accepting slower performance. The 5080 may be fine for gaming and many rendering tasks, but it does not meet the same VRAM requirement for your stated workloads.
For gaming, the RTX 5080 is relatively close to the 4090 and has newer-generation features, but it is not a true equivalent replacement. The 4090 still has more VRAM and generally stronger raw performance. If your practical choices are a 5080 or a refund worth about the same locally, the 5080 is probably the more useful option—and you could sell it later if necessary.
That comparison changes quite a bit when current used 4090 prices are roughly twice the price of a new 5080. Market value is more relevant here than the original invoice amount.
The offered cards are also a tier and model downgrade from a ROG Strix 4090. If ASUS will not provide a 4090, I would first ask for a 5090, a 5080 plus a substantial credit, or permission to buy an equivalent card with ASUS covering the difference. Whether that succeeds depends on the arbitration order and local consumer law, but a 16GB 5080 should not be described as technically equivalent.
A 5090 would be newer and faster, but it is also much more expensive now. ASUS may resist that argument, so documenting the VRAM requirement and the current replacement cost seems important.
If the original card's GPU and memory are still functional and only the cooler failed, another possible solution would have been returning the 4090 so you could replace the cooler or use a water block yourself. Since it has been in service for nine months, ask whether the original card can still be returned. If not, taking the 5080 may be the least damaging practical option, even though it is clearly a downgrade for AI work.
Exactly. A gaming-focused comparison can make the cards look fairly close, but memory capacity can determine whether an AI model runs at all. I would keep arguing for at least 24GB if that is a real requirement.