AMD Instinct MI455X vs NVIDIA GeForce RTX 4070 Mobile Comparison

Head-to-Head Benchmarks

The recorded data contains no direct head-to-head benchmark comparisons between the AMD Instinct MI455X and the NVIDIA GeForce RTX 4070 Mobile. The Instinct MI455X has no benchmark entries in the database, resulting in zero wins for either side in direct competition. This absence of measured performance data means the analysis must rely on architectural specifications and the RTX 4070 Mobile's established benchmark results against its own nearest rivals.

The RTX 4070 Mobile holds an average benchmark score of 27,435 across nine tests, placing it in the 73rd percentile of all GPUs tracked. Its nearest rival, the AMD Radeon RX 6700 XT, scores 27,425, a delta of 0%, meaning the two are statistically identical in overall performance. The NVIDIA GeForce RTX 3090 scores 27,565, which puts the RTX 4070 Mobile 0.5% behind that desktop-class card. Against the NVIDIA RTX PRO 4000 Blackwell, which scores 27,135, the RTX 4070 Mobile leads by 1.1%. The AMD Radeon Pro Vega 20 scores 27,839, placing the RTX 4070 Mobile 1.5% behind it.

The RTX 4070 Mobile's best individual benchmark result is a Geekbench OpenCL score of 109,197, with a Geekbench Vulkan score of 108,367 following closely. In Passmark tests, the DirectX 9 score of 223 and DirectX 11 score of 179 show legacy API performance, while DirectX 12 scores 85 and DirectX 10 scores 116. The GPU compute score reaches 8,399, and the G3D score is 19,587. The G2D score of 763 reflects 2D graphics throughput.

For the Instinct MI455X, the database records a 50th percentile ranking among all GPUs with an average benchmark score of zero, indicating no completed tests. The architecture's raw computational specifications, however, suggest a fundamentally different performance class. The MI455X delivers 157.3 TFLOPS of FP32 and FP16 compute, compared to 15.62 TFLOPS for the RTX 4070 Mobile in both precisions. This represents a 10.07x difference in raw floating-point throughput, though the absence of actual benchmark results prevents confirmation of real-world scaling.

FAQ

Q: Which GPU has a higher average benchmark score in the database?

A: The NVIDIA GeForce RTX 4070 Mobile has an average benchmark score of 27,435 across nine tests. The AMD Instinct MI455X has an average benchmark score of 0, as no benchmark results are recorded for it.

Q: How does the RTX 4070 Mobile compare to its closest rivals?

A: The RTX 4070 Mobile scores 27,435, which is statistically tied with the AMD Radeon RX 6700 XT at 27,425 (0% delta). It trails the NVIDIA GeForce RTX 3090 by 0.5% (27,565) and the AMD Radeon Pro Vega 20 by 1.5% (27,839), while leading the NVIDIA RTX PRO 4000 Blackwell by 1.1% (27,135).

Q: What is the memory capacity difference between these two GPUs?

A: The AMD Instinct MI455X features 432 GB of HBM4 memory on a 24,576-bit bus with 23.3 TB/s bandwidth. The NVIDIA GeForce RTX 4070 Mobile has 8 GB of GDDR6 memory on a 128-bit bus with 256.0 GB/s bandwidth.

Q: Which GPU has higher transistor density?

A: The NVIDIA GeForce RTX 4070 Mobile has a transistor density of 121.8 million transistors per square millimeter, while the AMD Instinct MI455X has 107.0 million per square millimeter.

Q: What are the release dates for these products?

A: The AMD Instinct MI455X has a recorded release date of July 22, 2026. The NVIDIA GeForce RTX 4070 Mobile was released on January 2, 2023.

Q: Does either GPU support DirectX or Vulkan APIs?

A: The NVIDIA GeForce RTX 4070 Mobile supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The AMD Instinct MI455X has no API support recorded, with DirectX, OpenGL, and Vulkan all listed as N/A.

Where Each One Wins

The RTX 4070 Mobile wins in every category where measured data exists. Its nine benchmark scores cover OpenCL, Vulkan, DirectX 10, 11, 12, 9, G2D, G3D, and compute workloads, providing a complete picture of consumer-grade graphics performance. The 73rd percentile ranking places it above the median GPU in the database, and its nearest rival comparisons show competitive parity with desktop cards like the RX 6700 XT and RTX 3090.

The Instinct MI455X wins on raw specification sheet metrics. Its 157.3 TFLOPS FP32 throughput exceeds the RTX 4070 Mobile's 15.62 TFLOPS by a factor of ten. The 432 GB memory capacity dwarfs the 8 GB available on the RTX 4070 Mobile, and the 23.3 TB/s bandwidth is 91 times higher than the 256.0 GB/s of the mobile card. The MI455X also uses a newer process node at 2 nm versus 5 nm, and its 2,400 MHz boost clock exceeds the RTX 4070 Mobile's 1,695 MHz boost.

For compute-oriented workloads that scale with raw FP32 or FP16 throughput, the MI455X's specifications indicate a clear advantage. For any workload requiring actual benchmark validation, graphics API support, or display output, the RTX 4070 Mobile is the only option with recorded functionality. The MI455X has no display outputs and no API support, limiting its applicability to compute-only environments.

Specification Differences

The two GPUs differ across nearly every recorded specification. The process node differs: the MI455X uses 2 nm while the RTX 4070 Mobile uses 5 nm, both fabricated by TSMC. Transistor counts are dramatically different, with the MI455X at 320,000 million transistors compared to 22,900 million for the RTX 4070 Mobile. Die size also differs substantially: 2,990 mm² for the MI455X versus 188 mm² for the RTX 4070 Mobile.

Memory configurations are in different classes entirely. The MI455X uses 432 GB of HBM4 with a 24,576-bit bus and 23.3 TB/s bandwidth. The RTX 4070 Mobile uses 8 GB of GDDR6 with a 128-bit bus and 256.0 GB/s bandwidth. Clock speeds show the MI455X with a 1,000 MHz base and 2,400 MHz boost, while the RTX 4070 Mobile has a 1,395 MHz base and 1,695 MHz boost. Memory clocks are 1,900 MHz (7.6 Gbps effective) for the MI455X and 2,000 MHz (16 Gbps effective) for the RTX 4070 Mobile.

Compute unit counts diverge sharply: the MI455X has 32,768 shading units, 1,024 TMUs, and zero ROPs, while the RTX 4070 Mobile has 4,608 shading units, 144 TMUs, and 48 ROPs. The RTX 4070 Mobile includes 36 ray tracing cores and 144 tensor cores; the MI455X has none recorded. Pixel rate for the MI455X is 0 MPixel/s versus 81.36 GPixel/s for the RTX 4070 Mobile. Texture rates are 2,457.6 GTexel/s and 244.1 GTexel/s respectively.

Power and form factor differ fundamentally. The MI455X has a TDP of 2,300 W with a suggested PSU of 2,700 W, while the RTX 4070 Mobile has a TDP of 115 W with no suggested PSU. The MI455X uses an EAM Module slot width, while the RTX 4070 Mobile is an IGP. Neither uses power connectors. Bus interfaces differ: PCIe 6.0 x16 for the MI455X versus PCIe 4.0 x8 for the RTX 4070 Mobile.

Architecture Differences

The AMD Instinct MI455X uses the CDNA 5.0 architecture, built around the MI450 256CU chip. This architecture is designed for compute acceleration, as evidenced by the absence of display outputs, graphics APIs, and ROPs. The 256 compute units translate to 32,768 shading units, with a 1:1 FP16 to FP32 ratio indicating no dedicated half-precision acceleration. The 2 nm TSMC process allows for 320,000 million transistors on a 2,990 mm² die, yielding a density of 107.0 million transistors per square millimeter.

The NVIDIA GeForce RTX 4070 Mobile uses the Ada Lovelace architecture with the AD106 chip. This architecture includes dedicated ray tracing cores (36) and tensor cores (144), along with 48 ROPs for rasterization output. The 5 nm TSMC process packs 22,900 million transistors onto a 188 mm² die, achieving a higher density of 121.8 million transistors per square millimeter. The architecture supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, making it fully compatible with consumer graphics workloads.

The MI455X belongs to the Instinct (MIx) generation with a predecessor of Radeon Instinct and no successor recorded. The RTX 4070 Mobile belongs to the GeForce 40-series with a predecessor of GeForce 30 Mobile and a successor of GeForce 50 Mobile. The MI455X has no production status recorded, while the RTX 4070 Mobile is marked as Active. The MI455X has no codename or series designation, while the RTX 4070 Mobile carries the GeForce 40-series label.

The fundamental architectural split is compute versus graphics. CDNA 5.0 prioritizes raw compute throughput with massive memory bandwidth, while Ada Lovelace balances compute with rasterization, ray tracing, and tensor operations. The MI455X's zero ROPs and no display outputs confirm its compute-only orientation. The RTX 4070 Mobile's 48 ROPs, ray tracing cores, and portable device-dependent display outputs confirm its graphics-first design.

The Verdict

The data indicates these are two GPUs built for entirely different purposes with no overlapping use cases. The RTX 4070 Mobile is a validated, actively produced mobile graphics processor with nine benchmark scores, a 73rd percentile ranking, and competitive parity with desktop GPUs like the RX 6700 XT and RTX 3090. Its 115 W TDP and IGP form factor make it suitable for portable devices, and its support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 ensures broad software compatibility.

The MI455X is a compute accelerator with specifications that place it in a different performance universe. Its 157.3 TFLOPS FP32 throughput, 432 GB of HBM4 memory, and 23.3 TB/s bandwidth target workloads like large-scale AI training or scientific simulation, not consumer graphics. The 2,300 W TDP and EAM Module form factor require data center infrastructure, and the absence of display outputs and graphics API support confirms that no interactive rendering is intended.

For users selecting a GPU for a laptop or portable workstation, the RTX 4070 Mobile is the only viable choice, backed by measured performance data. For users deploying a compute accelerator in a server environment, the MI455X offers specifications that exceed the RTX 4070 Mobile by an order of magnitude in compute throughput and memory capacity, though no benchmark data exists to validate real-world performance. The 50th percentile ranking for the MI455X reflects its zero benchmark score, not its theoretical capability. The choice between these two GPUs depends entirely on the workload: consumer graphics and portable computing point to the RTX 4070 Mobile, while massive-scale compute and memory-intensive tasks point to the MI455X.