AMD Instinct MI455X vs NVIDIA GeForce RTX 4070 Max-Q Comparison

Where Each One Wins

The benchmark data presents an unusual comparison: the AMD Instinct MI455X and the NVIDIA GeForce RTX 4070 Max-Q occupy entirely different performance domains, and the recorded wins reflect that separation. The AMD Instinct MI455X is an accelerator built for compute density, with a shading unit count of 32,768 versus the NVIDIA part's 4,608. The FP32 throughput of 157.3 TFLOPS on the AMD side dwarfs the 11.34 TFLOPS on the NVIDIA side, a 13.9x gap in raw shader output. The texture rate tells a similar story: 2,457.6 GTexel/s against 177.1 GTexel/s.

The NVIDIA GeForce RTX 4070 Max-Q wins in every category tied to graphics rendering and real-time interaction. It has 48 ROPs, a pixel rate of 59.04 GPixel/s, 36 RT cores, and 144 tensor cores. The AMD part has zero ROPs, zero RT cores, zero tensor cores, and a pixel rate of 0 MPixel/s. The NVIDIA chip also carries the full DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4 API stack, while the AMD accelerator lists N/A for all graphics APIs.

The use-case split is therefore absolute. The MI455X is a data-center compute module with no display outputs and no graphics API support. The RTX 4070 Max-Q is a mobile graphics processor with portable-device-dependent outputs. Any workload involving rasterization, ray tracing, tensor operations, or API-driven rendering falls to the NVIDIA part. Any workload involving massive parallel FP32 or FP16 compute, where the AMD part delivers 157.3 TFLOPS in both formats at a 1:1 ratio, falls to the AMD part.

The memory subsystem reinforces the split. The MI455X carries 432 GB of HBM4 across a 24,576-bit bus, yielding 23.3 TB/s of bandwidth. The RTX 4070 Max-Q has 8 GB of GDDR6 on a 128-bit bus, yielding 256.0 GB/s. That is a 91x difference in memory bandwidth, and a 54x difference in capacity. For memory-bound compute kernels, the AMD part is in a different class entirely. For graphics workloads requiring low latency and moderate bandwidth, the NVIDIA part is the only option with functional outputs.

The recorded data shows zero wins for either side in the head-to-head benchmark section, which is an empty set. The wins are inferred from the specification deltas. The AMD part wins on raw compute throughput, memory capacity, memory bandwidth, process node density, and transistor count. The NVIDIA part wins on pixel throughput, texture throughput relative to its shader count, ray tracing capability, tensor capability, API support, power efficiency, and portability.

Architecture Differences

The two processors come from fundamentally different design philosophies. The AMD Instinct MI455X uses the CDNA 5.0 architecture, built on the MI450 256CU chip at a 2 nm TSMC process node. The die size is 2,990 mm² with 320,000 million transistors, giving a transistor density of 107.0M per mm². The NVIDIA GeForce RTX 4070 Max-Q uses the Ada Lovelace architecture, built on the AD106 chip at a 5 nm TSMC process node. The die size is 188 mm² with 22,900 million transistors, giving a transistor density of 121.8M per mm².

The transistor density difference is notable: the NVIDIA chip packs 14.8M more transistors per square millimeter, indicating a denser logic design. However, the AMD chip has 14x more total transistors and a 15.9x larger die. The AMD approach favors massive parallel arrays, while the NVIDIA approach favors a balanced mix of specialized units.

The memory architectures are entirely different. The MI455X uses HBM4 with a 24,576-bit bus width, while the RTX 4070 Max-Q uses GDDR6 with a 128-bit bus. The AMD memory clock is 1900 MHz with 7.6 Gbps effective, while the NVIDIA memory clock is 2000 MHz with 16 Gbps effective. The NVIDIA part achieves higher per-pin data rates, but the AMD part's bus width is 192x wider, resulting in the 91x bandwidth advantage.

Core composition differs sharply. The MI455X has 32,768 shading units, 1,024 TMUs, and zero ROPs. The RTX 4070 Max-Q has 4,608 shading units, 144 TMUs, and 48 ROPs. The AMD part has no RT cores and no tensor cores. The NVIDIA part has 36 RT cores and 144 tensor cores. The AMD part's FP32 and FP16 both run at 157.3 TFLOPS with a 1:1 ratio. The NVIDIA part's FP32 and FP16 both run at 11.34 TFLOPS with a 1:1 ratio.

Clock speeds also diverge. The AMD base clock is 1000 MHz with a boost of 2400 MHz. The NVIDIA base clock is 735 MHz with a boost of 1230 MHz. The AMD part boosts to nearly double the NVIDIA's boost clock, which contributes to the FP32 advantage. The power envelope tells the opposite story: the MI455X is rated at 2300 W TDP with a suggested PSU of 2700 W, while the RTX 4070 Max-Q is rated at 35 W TDP. The NVIDIA part is 65x more power-efficient on paper.

The bus interface differs as well. The AMD part uses PCIe 6.0 x16, while the NVIDIA part uses PCIe 4.0 x8. The AMD part is an EAM Module slot width with no power connectors. The NVIDIA part is an IGP slot width with no power connectors. The AMD part has no display outputs. The NVIDIA part has portable-device-dependent outputs.

Head-to-Head Benchmarks

The recorded head-to-head benchmark array is empty, so the analysis must rely on the specification-derived performance indicators. The FP32 compute gap is the clearest signal: the MI455X delivers 157.3 TFLOPS against the RTX 4070 Max-Q's 11.34 TFLOPS. That is 13.9x higher FP32 throughput. The FP16 gap is identical because both parts run FP16 at a 1:1 ratio with FP32.

The texture rate comparison shows 2,457.6 GTexel/s for the AMD part versus 177.1 GTexel/s for the NVIDIA part, a 13.9x difference that mirrors the shader count ratio. The pixel rate is the opposite: the AMD part produces 0 MPixel/s because it has no ROPs, while the NVIDIA part produces 59.04 GPixel/s. Any workload that outputs to a display or requires rasterization will fail on the AMD part.

Memory bandwidth is the largest numerical gap. The MI455X delivers 23.3 TB/s, which is 91x the RTX 4070 Max-Q's 256.0 GB/s. The memory capacity gap is 432 GB versus 8 GB, a 54x difference. For large model inference or training data residency, the AMD part can hold 54x more data on-die. The NVIDIA part must rely on host memory or constant data streaming.

The clock behavior also matters. The MI455X boosts to 2400 MHz, which is 1.95x the NVIDIA's 1230 MHz boost. The base clocks are closer in ratio: 1000 MHz versus 735 MHz, a 1.36x difference. The AMD part's higher boost clock, combined with 7.1x more shading units, explains the compute advantage.

The transistor budget tells a story of specialization. The MI455X uses 320,000 million transistors for compute arrays and memory controllers. The RTX 4070 Max-Q uses 22,900 million transistors for a balanced mix of shaders, TMUs, ROPs, RT cores, and tensor cores. The NVIDIA part allocates die area to fixed-function units that the AMD part omits entirely.

The process node difference is smaller than the architecture difference. Both use TSMC, but the AMD part uses a 2 nm node versus the NVIDIA's 5 nm node. The AMD transistor density is 107.0M per mm², lower than the NVIDIA's 121.8M per mm², which suggests the AMD design uses more area per transistor, likely for large compute blocks and the massive HBM4 interface.

FAQ

Q: Which processor has higher FP32 compute throughput?

A: The AMD Instinct MI455X delivers 157.3 TFLOPS FP32, which is 13.9x the NVIDIA GeForce RTX 4070 Max-Q's 11.34 TFLOPS.

Q: Does the AMD Instinct MI455X support ray tracing?

A: No. The MI455X has zero RT cores and zero tensor cores. The NVIDIA GeForce RTX 4070 Max-Q has 36 RT cores and 144 tensor cores.

Q: How do the memory bandwidth figures compare?

A: The MI455X provides 23.3 TB/s via HBM4 on a 24,576-bit bus. The RTX 4070 Max-Q provides 256.0 GB/s via GDDR6 on a 128-bit bus. The AMD part has 91x the bandwidth.

Q: Can the AMD Instinct MI455X output to a display?

A: No. The MI455X has no display outputs and lists N/A for DirectX, OpenGL, and Vulkan. The RTX 4070 Max-Q has portable-device-dependent outputs and supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: What is the power consumption difference?

A: The MI455X is rated at 2300 W TDP with a suggested PSU of 2700 W. The RTX 4070 Max-Q is rated at 35 W TDP. The NVIDIA part uses 65x less power.

Q: Which processor has more shading units?

A: The MI455X has 32,768 shading units. The RTX 4070 Max-Q has 4,608 shading units. The AMD part has 7.1x more.

Specification Differences

| Field | AMD Instinct MI455X | NVIDIA GeForce RTX 4070 Max-Q |

|-------|---------------------|-------------------------------|

| Architecture | CDNA 5.0 | Ada Lovelace |

| Process Node | 2 nm | 5 nm |

| Foundry | TSMC | TSMC |

| Transistors | 320,000 million | 22,900 million |

| Die Size | 2990 mm² | 188 mm² |

| Transistor Density | 107.0M / mm² | 121.8M / mm² |

| Base Clock | 1000 MHz | 735 MHz |

| Boost Clock | 2400 MHz | 1230 MHz |

| Memory Clock | 1900 MHz, 7.6 Gbps effective | 2000 MHz, 16 Gbps effective |

| Memory Size | 432 GB | 8 GB |

| Memory Type | HBM4 | GDDR6 |

| Memory Bus Width | 24576 bit | 128 bit |

| Memory Bandwidth | 23.3 TB/s | 256.0 GB/s |

| Shading Units | 32768 | 4608 |

| TMUs | 1024 | 144 |

| ROPs | 0 | 48 |

| RT Cores | None | 36 |

| Tensor Cores | None | 144 |

| Pixel Rate | 0 MPixel/s | 59.04 GPixel/s |

| Texture Rate | 2,457.6 GTexel/s | 177.1 GTexel/s |

| FP32 | 157.3 TFLOPS | 11.34 TFLOPS |

| FP16 | 157.3 TFLOPS (1:1) | 11.34 TFLOPS (1:1) |

| TDP | 2300 W | 35 W |

| Slot Width | EAM Module | IGP |

| Power Connectors | None | None |

| Suggested PSU | 2700 W | None |

| Bus Interface | PCIe 6.0 x16 | PCIe 4.0 x8 |

| Display Outputs | No outputs | Portable Device Dependent |

| DirectX | N/A | 12 Ultimate (12_2) |

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.4 |

| Release Date | 2026-07-22 | 2023-01-02 |

| Production Status | Not specified | Active |

| Predecessor | Radeon Instinct | GeForce 30 Mobile |

| Successor | None specified | GeForce 50 Mobile |