GPU Comparison
Select up to 2 GPUs to analyze their pricing, performance, and specifications side-by-side.
The Radeon RX 6400 is significantly faster than the Radeon R9 390, leading by roughly 20% in our performance index.
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Radeon RX 6400 vs Radeon R9 390: In-Depth Breakdown
Performance: Radeon RX 6400 vs Radeon R9 390
The Radeon RX 6400 is significantly faster, around 20% ahead of the Radeon R9 390. Both cards sit in the same broad class, well suited to entry-level 1080p.
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 R9 390 or Radeon RX 6400?
The Radeon RX 6400 is the faster card by about 20%. 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.