AMD Radeon RX 6600 XT vs AMD Radeon RX 6800M Comparison

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon RX 6800M leads with an average benchmark score of 28,874, while the AMD Radeon RX 6600 XT averages 24,442. This places the RX 6800M in the 74th percentile of all GPUs, compared to the 70th percentile for the RX 6600 XT.

Q: How do the two cards compare in DirectX 12 performance?

A: In the 3DMark Steel Nomad DX12 test, the RX 6800M scores 2,238 versus 1,804 for the RX 6600 XT, a 24.1% advantage for the mobile card. However, in PassMark's DirectX 12 test, the RX 6800M leads by a smaller margin: 65 versus 61, a 6.6% difference.

Q: Which GPU wins in Geekbench compute tests?

A: The RX 6800M wins all three Geekbench tests. It scores 113,721 in Metal (28.2% ahead), 94,766 in Vulkan (30.9% ahead), and 87,621 in OpenCL (8.8% ahead) compared to the RX 6600 XT's respective scores of 88,720, 72,417, and 80,503.

Q: Where does the RX 6600 XT outperform the RX 6800M?

A: The RX 6600 XT wins in six of the eleven head-to-head tests. Its largest victories come in PassMark G2D (912 vs 538, a 41% lead), PassMark GPU Compute (7,520 vs 5,032, a 33.1% lead), and PassMark DirectX 9 (194 vs 147, a 24.2% lead). It also wins PassMark G3D, DirectX 10, and DirectX 11.

Q: What are the closest rivals to each card in the database?

A: The RX 6800M's nearest rivals are the AMD Radeon RX 570 (0.4% higher average score), AMD Radeon RX 470 (0.4% lower), AMD Radeon R9 M295X (1% higher), and Intel Arc A370M (1% lower). The RX 6600 XT's nearest rivals include the NVIDIA GeForce GTX 1630 (0.7% higher), Intel Arc A350M (0.8% lower), NVIDIA GeForce GTX 780 Ti (0.8% higher), and NVIDIA GeForce RTX 2080 SUPER (1.1% higher).

Q: What is the memory configuration difference between the two?

A: The RX 6800M has 12 GB of GDDR6 memory on a 192-bit bus, delivering 384.0 GB/s of bandwidth. The RX 6600 XT has 8 GB of GDDR6 on a 128-bit bus, providing 256.0 GB/s. Both run at 2000 MHz with 16 Gbps effective speed.

The Verdict

The data presents two distinct profiles. The AMD Radeon RX 6800M is the stronger overall performer in modern graphics workloads, with an average benchmark score 18.1% higher than the RX 6600 XT (28,874 vs 24,442). Its wins in 3DMark Steel Nomad DX12 and all three Geekbench tests indicate superiority in current-generation APIs and compute-oriented tasks.

The AMD Radeon RX 6600 XT, despite its lower average score, dominates in legacy DirectX tests and 2D workloads. It wins PassMark DirectX 9, DirectX 10, DirectX 11, G2D, G3D, and GPU Compute. This makes it the stronger choice for older game titles and compute workloads that rely on traditional rasterization paths.

For users prioritizing modern game engines, Vulkan-based titles, or Metal environments, the RX 6800M is clearly superior. Its 12 GB frame buffer and wider memory bus provide a structural advantage in texture-heavy scenarios. The RX 6600 XT, conversely, suits workloads that are not GPU-memory-bound and favor its higher boost clock and pixel rate.

The RX 6800M sits at the 74th percentile of all GPUs, while the RX 6600 XT sits at the 70th. Both are end-of-life products, but the RX 6800M's nearest rivals (RX 570, RX 470, R9 M295X, Arc A370M) all fall within a 1% band of its average score, indicating a tightly contested performance tier. The RX 6600 XT's rivals (GTX 1630, Arc A350M, GTX 780 Ti, RTX 2080 SUPER) similarly cluster within 1.1%.

Head-to-Head Benchmarks

The RX 6800M wins five of the eleven recorded benchmarks, but its victories tend to be in tests that carry more weight for modern gaming. The 3DMark Steel Nomad DX12 result is decisive: 2,238 versus 1,804, a 24.1% margin. This test stresses DirectX 12 Ultimate features, and the RX 6800M's 40 ray tracing cores versus 32 on the RX 6600 XT likely contribute to this gap.

Geekbench results amplify the same pattern. In Metal, the RX 6800M posts 113,721 against 88,720, a 28.2% lead. Vulkan shows the largest gap at 30.9% (94,766 vs 72,417). OpenCL is closer but still favors the RX 6800M: 87,621 versus 80,503, an 8.8% difference. These compute-focused benchmarks align with the RX 6800M's higher shading unit count (2,560 vs 2,048) and FP32 throughput (12.24 TFLOPS vs 10.60 TFLOPS).

The RX 6600 XT's wins are concentrated in PassMark's suite. Its most significant victory is in G2D, where 912 versus 538 represents a 41% advantage. GPU Compute follows with 7,520 versus 5,032, a 33.1% lead. DirectX 9 shows a 24.2% edge (194 vs 147), and DirectX 11 shows a 22.1% edge (163 vs 127). DirectX 10 is closer at 7.3% (109 vs 101). In G3D, the RX 6600 XT leads 16,461 versus 13,261, a 19.4% margin.

The only test where the RX 6800M wins narrowly is PassMark DirectX 12: 65 versus 61, a 6.6% difference. This contrasts sharply with the 24.1% margin in 3DMark Steel Nomad DX12, suggesting the two DirectX 12 tests measure different aspects of the pipeline.

Overall, the database records 5 wins for the RX 6800M and 6 for the RX 6600 XT. The RX 6800M's wins are larger on average in modern workloads, while the RX 6600 XT's wins dominate legacy and 2D tests.

Specification Differences

The two GPUs share the same 7 nm process node from TSMC, RDNA 2.0 architecture, and API support (DirectX 12 Ultimate, OpenGL 4.6, Vulkan 1.4). They diverge substantially in most other hardware parameters.

The RX 6800M uses the Navi 22 chip with 17,200 million transistors on a 335 mm² die, giving a transistor density of 51.3M per mm². The RX 6600 XT uses Navi 23 with 11,060 million transistors on a 237 mm² die, a density of 46.7M per mm². The RX 6800M is physically larger and packs 55.5% more transistors.

Clock behavior differs. The RX 6800M has a higher base clock (2,116 MHz vs 1,968 MHz) and game clock (2,300 MHz vs 2,359 MHz is actually lower, corrected: the RX 6800M's game clock is 2,300 MHz, the RX 6600 XT's is 2,359 MHz). The RX 6600 XT has the higher boost clock at 2,589 MHz versus 2,390 MHz. Both run memory at 2000 MHz with 16 Gbps effective.

Memory capacity and bandwidth favor the RX 6800M: 12 GB on a 192-bit bus with 384.0 GB/s versus 8 GB on a 128-bit bus with 256.0 GB/s. This is a 50% bandwidth advantage for the RX 6800M.

Compute resources differ: the RX 6800M has 2,560 shading units, 160 TMUs, 64 ROPs, and 40 RT cores. The RX 6600 XT has 2,048 shading units, 128 TMUs, 64 ROPs, and 32 RT cores. The RX 6800M's texture rate is 382.4 GTexel/s versus 331.4 GTexel/s, and its FP32 output is 12.24 TFLOPS versus 10.60 TFLOPS. FP16 follows the same ratio: 24.47 TFLOPS versus 21.21 TFLOPS, both at 2:1.

Pixel rates favor the RX 6600 XT: 165.7 GPixel/s versus 153.0 GPixel/s, driven by its higher boost clock. Power draw differs as well: the RX 6800M is rated at 145 W with no power connectors and IGP slot width, while the RX 6600 XT is rated at 160 W, uses a single 8-pin connector, dual-slot design, and lists a 450 W suggested PSU.

The RX 6600 XT is a physical card measuring 190 mm by 110 mm by 40 mm, with display outputs of 1x HDMI 2.1 and 3x DisplayPort 1.4a. The RX 6800M's outputs are portable device dependent. Bus interfaces differ: PCIe 4.0 x16 for the RX 6800M versus PCIe 4.0 x8 for the RX 6600 XT.

Architecture Differences

Both cards implement RDNA 2.0, but they use different silicon. The RX 6800M is built on Navi 22, while the RX 6600 XT uses Navi 23. The RX 6800M belongs to the Navi Mobile generation (RX 6000M), whereas the RX 6600 XT is part of the Navi II generation (RX 6000).

The transistor budgets reflect the die size disparity. Navi 22 packs 17,200 million transistors into 335 mm², achieving a density of 51.3M per mm². Navi 23 contains 11,060 million transistors in 237 mm², with a density of 46.7M per mm². The RX 6800M's larger die accommodates 25% more shading units (2,560 vs 2,048), 25% more TMUs (160 vs 128), and 25% more RT cores (40 vs 32). ROP counts are identical at 64.

Memory architecture is a key differentiator. The RX 6800M uses a 192-bit interface with 12 GB GDDR6, yielding 384.0 GB/s. The RX 6600 XT uses a 128-bit interface with 8 GB GDDR6, yielding 256.0 GB/s. This is a 33% bandwidth deficit for the RX 6600 XT, which can impact high-resolution texture streaming and memory-heavy workloads.

Both chips are fabricated by TSMC at 7 nm and support the same API set: DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. Neither has tensor cores, and both rely on RDNA 2's ray acceleration blocks. The RX 6800M's 40 RT cores versus 32 on the RX 6600 XT explains its stronger 3DMark Steel Nomad DX12 result.

The RX 6800M's predecessor is Polaris Mobile, while the RX 6600 XT's predecessor is Navi and its successor is Navi III. The RX 6800M has no listed successor. Both are marked end-of-life, with the RX 6800M released on 2021-05-30 and the RX 6600 XT on 2021-07-29. The RX 6600 XT carries a launch MSRP of 379 USD.

Clock strategy differs meaningfully. The RX 6600 XT boosts to 2,589 MHz, which is 199 MHz higher than the RX 6800M's 2,390 MHz boost. This explains why the RX 6600 XT achieves a higher pixel rate (165.7 GPixel/s vs 153.0 GPixel/s) despite having fewer ROPs at the same count. However, the RX 6800M's higher base clock (2,116 MHz vs 1,968 MHz) and game clock (2,300 MHz vs 2,359 MHz, note the RX 6600 XT is actually higher here) indicate different sustained performance profiles.

Power delivery separates the two physically. The RX 6800M is an integrated mobile part at 145 W with no external connectors. The RX 6600 XT is a discrete dual-slot card at 160 W requiring one 8-pin connector and a 450 W PSU. The RX 6600 XT also offers fixed display outputs, while the RX 6800M's outputs depend on the host device.