GPU comparison · 1080p benchmark
RTX 4090 24GB recorded 621 FPS against 368 FPS for RX 6900 XT 16GB. These are continuous 1080p benchmark averages, not predicted FPS in any particular game.
RX 6900 XT 16GB
368Benchmark FPS at 1080p- Our rating
- 76.7 / 100
- Graphics memory
- 16GB
- Released
- December 2020
- GPUsed cards tested
- 22
RTX 4090 24GB
621Benchmark FPS at 1080p- Our rating
- 92.2 / 100
- Graphics memory
- 24GB
- Released
- October 2022
- GPUsed cards tested
- 127
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What does this comparison mean?
The RTX 4090 24GB leads the RX 6900 XT 16GB and adds 8GB of memory. The move changes vendor and GPU tier; this continuous result does not establish AI, rendering or ray-tracing speed, even when the extra capacity is relevant to those tasks.
RX 6900 XT 16GB has 16GB and RTX 4090 24GB has 24GB of graphics memory. Memory capacity, board dimensions, power connectors and the price of a particular used card are separate from this benchmark. Compare the exact item before deciding whether to upgrade.
The two GPUs in context
RX 6900 XT 16GB
The RX 6900 XT arrived in December 2020 with RDNA 2 architecture and 16GB of GDDR6. It uses the full Navi 21 configuration, rather than the reduced configuration of the RX 6800 XT.
RTX 4090 24GB
The RTX 4090 launched in October 2022 with Ada Lovelace architecture and 24GB of GDDR6X.
Release and feature sources: RX 6900 XT 16GB source · RTX 4090 24GB source.
How the figures are compared
Both FPS figures come from the owner-supplied GPUsed benchmark dataset. GPUsed reports a continuous FurMark run at 1080p for its physical-card checks. The percentage compares the higher model average with the lower one using the original FPS values. Our rating uses a compressed scale, with the fastest GPU at 100; it is separate from the percentage difference. A benchmark result does not predict gaming FPS.
GPUsed reports its physical-card checks typically last 30 to 60 minutes while temperature and stability are checked. The owner supplied the model-level FPS workbook on 2 October 2026; this benchmark dataset was last reconciled 3 October 2026. Historical cards tested are separate from the number of FPS runs behind a model average. Full benchmark method.