AMD Radeon RX 6600 vs AMD Radeon RX 7900 XTX Comparison

The AMD Radeon RX 7900 XTX and the AMD Radeon RX 6600 occupy opposite ends of the Radeon spectrum, but the benchmark data quantifies just how vast that gap truly is. Across ten head-to-head tests, the RX 7900 XTX claims a clean sweep, yet the RX 6600 remains a relevant data point for understanding scaling within AMD’s lineup. The results show a flagship built for absolute throughput against a mainstream part designed for efficiency, and the numbers reveal the architectural and generational chasm between them.

Head-to-Head Benchmarks

The most decisive victory for the RX 7900 XTX comes in the 3DMark Steel Nomad DX12 test, where it scores 6841 against the RX 6600’s 1492. That is a delta of 358.5%, meaning the newer card delivers more than four and a half times the performance in this modern DirectX 12 workload. No other test approaches this margin, but the pattern of dominance is consistent.

In Passmark’s GPU Compute benchmark, the RX 7900 XTX posts 17689 versus 6554, a 169.9% advantage. This reflects the massive difference in raw compute resources, as the flagship carries 6144 shading units against the RX 6600’s 1792. The Passmark DirectX 12 test shows a 156.9% lead (131 vs 51), while DirectX 11 delivers a 134.2% gap (356 vs 152). These legacy API results still favor the bigger chip by wide margins, though the absolute scores are lower across the board.

The Geekbench results show a tighter but still decisive spread. In OpenCL, the RX 7900 XTX scores 50465 versus 28850, a 74.9% improvement. Vulkan narrows the gap further to 26.6%, with scores of 85612 and 67623 respectively. This suggests that the RX 6600’s RDNA 2 architecture handles Vulkan relatively better than its older DirectX counterparts, but it still cannot overcome the RX 7900 XTX’s hardware advantage.

Passmark’s legacy DirectX 9 test shows a 67.5% lead (330 vs 197), while DirectX 10 comes in at 74.7% (166 vs 95). The 2D test is the closest of all, with the RX 7900 XTX scoring 1267 against 889, a 42.5% delta. Even in a workload that does not stress the GPU’s core compute, the newer card’s higher memory bandwidth and larger cache hierarchy provide a measurable edge. The Passmark G3D score of 31238 for the RX 7900 XTX versus 15096 for the RX 6600 represents a 106.9% doubling, reinforcing that this is not a marginal upgrade but a generational leap.

Architecture Differences

The two cards are built on different nodes and architectures. The RX 7900 XTX uses the Navi 31 chip on TSMC’s 5 nm process, while the RX 6600 uses Navi 23 on a 7 nm node. This process shrink allows the flagship to pack 57,700 million transistors into a 529 mm² die, achieving a transistor density of 109.1M per mm². The RX 6600, by contrast, contains 11,060 million transistors on a 237 mm² die, with a density of 46.7M per mm². The 5 nm node is not just smaller; it enables a 5.2x increase in transistor count with only a 2.2x increase in die area.

Architecturally, the RX 7900 XTX is RDNA 3.0, while the RX 6600 is RDNA 2.0. This generation shift brings changes to the compute unit design and clock behavior. The RX 7900 XTX has a base clock of 1929 MHz and a boost clock of 2498 MHz, with a game clock of 2365 MHz. The RX 6600 runs at 1626 MHz base and 2491 MHz boost, with a game clock of 2044 MHz. The boost clocks are nearly identical, but the RX 7900 XTX sustains higher clocks across the board, particularly in game scenarios where it runs 321 MHz faster.

Memory configurations differ sharply. The RX 7900 XTX uses 24 GB of GDDR6 on a 384-bit bus, delivering 960.0 GB/s of bandwidth at 20 Gbps effective. The RX 6600 has 8 GB of GDDR6 on a 128-bit bus, with 224.0 GB/s at 14 Gbps. That is a 4.3x bandwidth advantage for the flagship, which matters in 4K textures and compute-heavy scenes. The RX 7900 XTX also has 96 ray tracing cores versus the RX 6600’s 28, a 3.4x increase in RT hardware.

The render output units tell a similar story: 192 ROPs on the RX 7900 XTX against 64 on the RX 6600, enabling a pixel rate of 479.6 GPixel/s versus 159.4 GPixel/s. Texture units are 384 versus 112, yielding 959.2 GTexel/s against 279.0 GTexel/s. The FP32 throughput is 61.39 TFLOPS versus 8.928 TFLOPS, a 6.9x gap. The RX 7900 XTX also uses a PCIe 4.0 x16 interface, while the RX 6600 is limited to x8 lanes, which can matter in bandwidth-sensitive tasks.

Where Each One Wins

The RX 7900 XTX wins in every benchmark category, but the margins tell a story about where each card is best suited. The largest deltas are in synthetic compute and modern API tests, which align with the flagship’s intended role as a high-resolution gaming and workstation card. Its 24 GB frame buffer and 960 GB/s bandwidth make it suitable for 4K gaming, AI inference, and content creation workloads that demand large memory pools.

The RX 6600, despite losing all ten head-to-head tests, holds its own in specific scenarios. Its 132 W TDP and single 8-pin connector make it a far lighter power load than the RX 7900 XTX’s 355 W and dual 8-pin requirement. The data shows it is competitive in Vulkan, where the delta narrows to 26.6%, and in 2D workloads, where the gap is just 42.5%. For users prioritizing efficiency per watt or building in small form factor cases, the RX 6600’s 190 mm length and 40 mm width against the RX 7900 XTX’s 287 mm length and 51 mm width are meaningful physical differences.

The RX 6600’s 63rd percentile ranking versus the RX 7900 XTX’s 64th percentile among all GPUs is surprising given the performance gap. The average benchmark scores are 19036 and 19410 respectively, a difference of only about 2%. This indicates that the RX 6600 punches above its weight in the aggregate, likely because its efficiency allows it to be paired with weaker CPUs without bottlenecking, whereas the RX 7900 XTX requires a high-end platform to reach its potential. The nearest rivals for the RX 6600 include the NVIDIA Quadro K6000 and RTX 4050 Mobile, all within 0.4% of its average score, while the RX 7900 XTX competes with the GTX 1060 3 GB and TITAN Xp in the same aggregate neighborhood.

FAQ

Q: Which card has the higher boost clock?

A: The RX 7900 XTX boosts to 2498 MHz, while the RX 6600 reaches 2491 MHz. The difference is just 7 MHz, making them nearly identical in peak clock speed.

Q: How much faster is the RX 7900 XTX in DirectX 12?

A: In the 3DMark Steel Nomad DX12 test, the RX 7900 XTX scores 6841 versus 1492, a 358.5% advantage. In Passmark’s DX12 test, the lead is 156.9% (131 vs 51).

Q: What is the memory bandwidth difference?

A: The RX 7900 XTX delivers 960.0 GB/s over a 384-bit bus, while the RX 6600 provides 224.0 GB/s over a 128-bit bus. That is a 4.3x bandwidth advantage for the flagship.

Q: Which card has more ray tracing cores?

A: The RX 7900 XTX has 96 RT cores, compared to 28 on the RX 6600. This is a 3.4x increase in dedicated ray tracing hardware.

Q: Do both cards support the same APIs?

A: Yes, both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. Their API feature sets are identical, despite the architectural differences.

Q: How do their average benchmark scores compare?

A: The RX 7900 XTX has an average benchmark score of 19410, while the RX 6600 scores 19036. This places them within 2% of each other in the aggregate, despite the RX 7900 XTX winning all ten head-to-head tests.

Specification Differences

The two cards differ in nearly every measurable specification. The RX 7900 XTX uses the Navi 31 chip on a 5 nm process, while the RX 6600 uses Navi 23 on 7 nm. Transistor counts are 57,700 million versus 11,060 million, and die sizes are 529 mm² versus 237 mm². Base clocks are 1929 MHz versus 1626 MHz, game clocks are 2365 MHz versus 2044 MHz, and memory clocks are 2500 MHz versus 1750 MHz.

Memory capacity is 24 GB versus 8 GB, with bus widths of 384-bit versus 128-bit and bandwidths of 960.0 GB/s versus 224.0 GB/s. The shading units number 6144 against 1792, TMUs are 384 versus 112, and ROPs are 192 versus 64. Ray tracing cores are 96 versus 28. Pixel rates are 479.6 GPixel/s versus 159.4 GPixel/s, and texture rates are 959.2 GTexel/s versus 279.0 GTexel/s. FP32 compute is 61.39 TFLOPS versus 8.928 TFLOPS, and FP16 is 122.8 TFLOPS versus 17.86 TFLOPS.

Power draw is 355 W versus 132 W, with the RX 7900 XTX requiring 2x 8-pin connectors and a 750 W PSU, while the RX 6600 uses a single 8-pin and 300 W PSU. The bus interface is PCIe 4.0 x16 versus x8. Display outputs differ: the RX 7900 XTX offers 1x HDMI 2.1, 2x DisplayPort 2.1, and 1x USB Type-C, while the RX 6600 provides 1x HDMI 2.1 and 3x DisplayPort 1.4a. Dimensions are 287 mm x 110 mm x 51 mm versus 190 mm x 110 mm x 40 mm. Both are dual-slot cards. The RX 7900 XTX launched at 999 USD, while the RX 6600 launched at 329 USD.