AMD Radeon RX 6600M vs NVIDIA RTX A4000 Mobile Comparison

# AMD Radeon RX 6600M vs NVIDIA RTX A4000 Mobile

The AMD Radeon RX 6600M and NVIDIA RTX A4000 Mobile represent two fundamentally different approaches to mobile graphics, with the AMD part built on RDNA 2.0 targeting gaming workloads while the NVIDIA part leverages the Ampere architecture with professional-grade compute features. The head-to-head benchmark data shows a near-split decision: NVIDIA wins 5 of 9 tests, AMD wins 4, yet the magnitude of those wins tells a more nuanced story about where each GPU excels. Both parts are end-of-life products, with the AMD released on 2021-05-30 and the NVIDIA on 2021-04-11, and both sit in similar overall performance percentiles—68th for AMD, 66th for NVIDIA—despite their architectural differences.

Where Each One Wins

The AMD Radeon RX 6600M dominates in legacy DirectX 9 workloads, posting a 17.2% advantage over the RTX A4000 Mobile (184 vs 157). This pattern extends to DirectX 11, where AMD leads by 7.1% (136 vs 127), suggesting the RDNA 2.0 architecture retains strong performance in older API environments. The AMD part also wins decisively in 2D graphics operations, achieving 728 in Passmark G2D versus 585 for NVIDIA—a 24.4% gap that indicates superior raw 2D rendering throughput. In Vulkan, AMD edges out a narrow 1% victory (73740 vs 73002), showing near-parity in this modern cross-platform API.

The NVIDIA RTX A4000 Mobile, meanwhile, takes the compute-heavy and modern API workloads. Its Geekbench OpenCL score of 97178 crushes AMD's 67765—a 30.3% difference that highlights NVIDIA's advantage in general-purpose compute. The RTX A4000 Mobile also wins DirectX 12 by 21.2% (66 vs 52) and DirectX 10 by 17.1% (105 vs 87). In the overall 3D graphics benchmark, Passmark G3D, NVIDIA leads by 5.9% (14796 vs 13929), and in GPU compute it extends that lead to 11.7% (6394 vs 5646). The pattern is clear: AMD wins where older APIs and 2D operations dominate, while NVIDIA wins where modern APIs, compute, and raw 3D throughput matter most.

Architecture Differences

The two GPUs come from different foundries and process nodes, which fundamentally shapes their characteristics. AMD uses TSMC's 7 nm process with 11,060 million transistors packed into a 237 mm² die, yielding a transistor density of 46.7 million per square millimeter. NVIDIA's GA104 chip uses Samsung's 8 nm process, with 17,400 million transistors on a much larger 392 mm² die, giving a slightly lower density of 44.4 million per square millimeter. The AMD chip is Navi 23 from the Radeon RX 6000 series, while NVIDIA's is GA104 from the Ampere generation.

Clock speeds reveal another divergence: AMD runs much higher frequencies, with a base of 2068 MHz and boost of 2416 MHz, plus a game clock of 2177 MHz. NVIDIA's RTX A4000 Mobile operates at a more conservative 1140 MHz base and 1680 MHz boost. Memory clocks differ similarly—AMD's GDDR6 runs at 1750 MHz (14 Gbps effective) versus NVIDIA's 1500 MHz (12 Gbps effective). Yet NVIDIA compensates with a 256-bit memory bus versus AMD's 128-bit, delivering 384.0 GB/s bandwidth against AMD's 224.0 GB/s. Both have 8 GB of GDDR6.

The compute architectures diverge sharply. AMD fields 1792 shading units, 112 texture mapping units, and 64 ROPs, with 28 ray tracing cores and no tensor cores. NVIDIA counters with 5120 shading units, 160 TMUs, and 80 ROPs, plus 40 ray tracing cores and 160 tensor cores. This explains NVIDIA's FP32 throughput of 17.20 TFLOPS versus AMD's 8.659 TFLOPS—exactly double. Interestingly, AMD's FP16 performance is also 17.32 TFLOPS (2:1 ratio), matching NVIDIA's 17.20 TFLOPS (1:1 ratio). Power envelopes differ modestly: AMD at 100 W TDP versus NVIDIA at 115 W. The bus interface also differs, with AMD using PCIe 4.0 x8 and NVIDIA using PCIe 4.0 x16.

FAQ

Q: Which GPU has higher raw compute performance?

A: The NVIDIA RTX A4000 Mobile has double the FP32 throughput at 17.20 TFLOPS versus AMD's 8.659 TFLOPS, and it wins Geekbench OpenCL by 30.3% (97178 vs 67765).

Q: Does the AMD RX 6600M win any modern API benchmarks?

A: Yes, it wins Vulkan by 1% (73740 vs 73002), though this is a narrow margin. Its bigger wins come in older APIs like DirectX 9 (17.2% ahead) and DirectX 11 (7.1% ahead).

Q: How do memory bandwidths compare between the two?

A: The NVIDIA RTX A4000 Mobile has a 256-bit bus delivering 384.0 GB/s, while the AMD RX 6600M has a 128-bit bus delivering 224.0 GB/s. This gives NVIDIA a 71.4% bandwidth advantage.

Q: Which GPU has more shading units and ray tracing cores?

A: NVIDIA has 5120 shading units and 40 ray tracing cores, while AMD has 1792 shading units and 28 ray tracing cores. NVIDIA also has 160 tensor cores, which AMD completely lacks.

Q: What are the transistor counts and die sizes?

A: NVIDIA's GA104 has 17,400 million transistors on a 392 mm² die, while AMD's Navi 23 has 11,060 million transistors on a 237 mm² die. AMD achieves higher density at 46.7M/mm² versus NVIDIA's 44.4M/mm².

Q: Which GPU has better 2D graphics performance?

A: The AMD RX 6600M wins Passmark G2D by 24.4% (728 vs 585), indicating stronger 2D rendering capabilities despite NVIDIA's overall 3D advantage.

Specification Differences

The two GPUs differ on nearly every key specification. Process node: AMD uses 7 nm from TSMC, NVIDIA uses 8 nm from Samsung. Transistor count: 11,060 million for AMD versus 17,400 million for NVIDIA. Die size: 237 mm² versus 392 mm². Base clock: 2068 MHz versus 1140 MHz. Boost clock: 2416 MHz versus 1680 MHz. Memory clock: 1750 MHz (14 Gbps) versus 1500 MHz (12 Gbps). Memory bus width: 128-bit versus 256-bit. Memory bandwidth: 224.0 GB/s versus 384.0 GB/s. Shading units: 1792 versus 5120. Texture mapping units: 112 versus 160. ROPs: 64 versus 80. Ray tracing cores: 28 versus 40. Tensor cores: none versus 160. Pixel rate: 154.6 GPixel/s versus 134.4 GPixel/s. Texture rate: 270.6 GTexel/s versus 268.8 GTexel/s. FP32: 8.659 TFLOPS versus 17.20 TFLOPS. FP16: 17.32 TFLOPS versus 17.20 TFLOPS. TDP: 100 W versus 115 W. Bus interface: PCIe 4.0 x8 versus PCIe 4.0 x16.

Head-to-Head Benchmarks

The most dramatic result is Geekbench OpenCL, where NVIDIA wins by 30.3% (97178 vs 67765). This is the single largest performance gap in either direction and speaks to NVIDIA's compute architecture advantage. The RTX A4000 Mobile also secures a 21.2% win in Passmark DirectX 12 (66 vs 52), a significant margin for a modern graphics API. In DirectX 10, NVIDIA leads by 17.1% (105 vs 87), and in GPU compute by 11.7% (6394 vs 5646). The Passmark G3D result shows NVIDIA ahead by 5.9% (14796 vs 13929), a moderate but consistent 3D advantage.

AMD's largest victory comes in Passmark G2D, where it wins by 24.4% (728 vs 585)—a surprising margin given NVIDIA's overall hardware advantage. The RX 6600M also wins DirectX 9 by 17.2% (184 vs 157) and DirectX 11 by 7.1% (136 vs 127). In Vulkan, AMD's 1% edge (73740 vs 73002) is nearly negligible but technically a win. Notably, AMD's average benchmark score of 23273 is higher than NVIDIA's 21379, yet NVIDIA wins more head-to-head tests. This paradox suggests AMD's strength is concentrated in specific legacy workloads, while NVIDIA distributes its performance more evenly across modern and compute tasks.

The Verdict

The data points to a clear use-case split. The NVIDIA RTX A4000 Mobile is the choice for compute-heavy professional workloads, OpenCL applications, DirectX 12 gaming, and any task leveraging tensor cores or the 384.0 GB/s bandwidth. Its 30.3% OpenCL lead and 21.2% DirectX 12 advantage make it the stronger all-around modern GPU. The 5120 shading units and 160 tensor cores provide architectural headroom that AMD cannot match.

The AMD Radeon RX 6600M, however, wins for users prioritizing legacy DirectX 9 and DirectX 11 titles, 2D graphics work, or Vulkan applications where it holds a slight edge. Its 24.4% G2D advantage and 17.2% DirectX 9 lead suggest it handles older software stacks more efficiently. The lower 100 W TDP also makes it the more power-efficient choice.

For professional users running compute or modern APIs, the RTX A4000 Mobile is the clear winner. For gamers with older libraries or those who prioritize 2D performance and lower power draw, the RX 6600M holds distinct advantages. Neither GPU dominates outright—the 4-5 win split in NVIDIA's favor reflects a close contest where workload determines the victor. The NVIDIA part's higher average benchmark score of 21379 versus AMD's 23273 is actually lower, indicating AMD's wins are in high-scoring tests while NVIDIA's wins are in lower-scoring ones, which is worth considering for anyone weighing overall versus workload-specific performance.