GPU Comparison
Select up to 2 GPUs to analyze their pricing, performance, and specifications side-by-side.
The Radeon R9 390 is noticeably faster than the Radeon RX 6400, leading by roughly 14% in our performance index.
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Radeon R9 390 vs Radeon RX 6400: In-Depth Breakdown
Performance: Radeon R9 390 vs Radeon RX 6400
The Radeon R9 390 is noticeably faster, around 14% ahead of the Radeon RX 6400. Both cards sit in the same broad class, well suited to entry-level 1080p. The Radeon R9 390 packs 2,560 stream processors versus 768 on the Radeon RX 6400.
Power & Efficiency
The Radeon RX 6400 draws just 53W versus 275W for the Radeon R9 390, and it also delivers more performance per watt — so it runs cooler and quieter and needs less PSU headroom. Its more modern RDNA 2 architecture on a TSMC N6 process is part of why it does more with each watt.
VRAM & Future-Proofing
With 8GB against 4GB, the Radeon R9 390 has more headroom for 4K textures and memory-hungry creative/AI tasks where the Radeon RX 6400's 4GB can fall short. The Radeon R9 390's memory is also faster — 384 GB/s versus 128 GB/s (512-bit vs 64-bit bus) — which helps feed the GPU at 4K and with heavy textures.
Generation & Longevity
The Radeon RX 6400 is roughly 7 years newer than the Radeon R9 390 (RDNA 2 vs GCN 2.0), so it generally benefits from a more modern architecture and longer driver-support runway.
Which should you buy: Radeon RX 6400 or Radeon R9 390?
The Radeon R9 390 is the faster card by about 14%. With live pricing limited for this pair, base your decision on the spec differences above — particularly VRAM and power draw — and check current stock before buying.