AMD Instinct MI300X vs NVIDIA GeForce RTX 4080 Mobile Comparison

Head-to-Head Benchmarks

The database contains a single shared benchmark between these two accelerators: Geekbench OpenCL. The AMD Instinct MI300X posts a score of 317,994, while the NVIDIA GeForce RTX 4080 Mobile records 159,575. That gives the AMD part a 99.3% advantage, a near doubling of the raw compute score. In the head-to-head record, the MI300X takes the sole win, 1 to 0.

Interpreting that result against the broader field clarifies its meaning. The MI300X sits at the 100th percentile of all GPUs in the database, meaning no recorded part scores higher. Its nearest rival, the NVIDIA H200 NVL, averages 334,891, which is 5% higher, so the MI300X is just behind the top data-center part. The NVIDIA B200 also outranks it by 8% with a 345,482 average. However, the MI300X beats the NVIDIA L40S by 7.5% (295,763) and the NVIDIA RTX 6000 Ada Generation by 10.7% (287,237). In short, the MI300X is a top-tier compute device, even if it is not the absolute fastest in the database.

The RTX 4080 Mobile, by contrast, sits at the 81st percentile. Its average benchmark score of 38,135 is drastically lower, but that figure is skewed by several lightweight tests. Its nearest rivals in the database are all close: the NVIDIA GeForce MX570 averages 38,299 (-0.4%), the NVIDIA GeForce RTX 5080 Mobile averages 38,349 (-0.6%), and the NVIDIA GeForce RTX 4070 averages 37,648 (+1.3%). This clustering indicates that the RTX 4080 Mobile performs in a narrow band around these parts in aggregate, despite its much higher Geekbench OpenCL result. The gap between the two headline scores is the defining feature of this comparison: the MI300X delivers roughly double the OpenCL throughput of the mobile part.

Architecture Differences

The two chips share a manufacturing process but diverge sharply in every other architectural choice. Both are built on a 5 nm process at TSMC, which is where the similarity ends.

The MI300X uses AMD's CDNA 3.0 architecture, designed for compute accelerators. Its die, codenamed Aqua Vanjaram, is enormous at 1017 mm² and packs 153,000 million transistors, yielding a density of 150.4 million transistors per square millimeter. It has 19,456 shading units and 1,216 texture mapping units, but no ROPs, no RT cores, and no tensor cores listed. Its pixel rate is recorded as 0 MPixel/s, which reflects its lack of display and rasterization hardware. Its texture rate is 2,553.6 GTexel/s. Floating-point throughput is identical for FP32 and FP16 at 81.72 TFLOPS each, a 1:1 ratio that is typical for CDNA parts where the FP16 path is not doubled.

The RTX 4080 Mobile uses NVIDIA's Ada Lovelace architecture, built for laptops. The AD104 die is 294 mm², roughly 29% of the MI300X's area, and contains 35,800 million transistors at a density of 121.8 million per square millimeter. It has 7,424 shading units, 232 TMUs, and 80 ROPs. Unlike the MI300X, it includes 58 RT cores and 232 tensor cores, enabling hardware-accelerated ray tracing and AI workloads. Its FP32 and FP16 throughput are both 24.72 TFLOPS, also at a 1:1 ratio. The pixel rate is 133.2 GPixel/s, and the texture rate is 386.3 GTexel/s.

Memory systems could hardly be more different. The MI300X uses 192 GB of HBM3 on a 8192-bit bus, delivering 5.32 TB/s of bandwidth. The RTX 4080 Mobile uses 12 GB of GDDR6 on a 192-bit bus, delivering 432.0 GB/s. That is a 12.3x difference in bandwidth and a 16x difference in capacity. The MI300X operates with a 1000 MHz base and 2100 MHz boost clock, while the RTX 4080 Mobile has a 1290 MHz base and 1665 MHz boost. Memory clocks are 1300 MHz (5.2 Gbps effective) for the MI300X versus 2250 MHz (18 Gbps effective) for the RTX 4080 Mobile.

Feature support also differs. The MI300X has no display outputs and lists no DirectX, OpenGL, or Vulkan support. The RTX 4080 Mobile supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, with display outputs described as portable device dependent. The bus interface is PCIe 5.0 x16 on the MI300X versus PCIe 4.0 x16 on the RTX 4080 Mobile.

The Verdict

The data indicates that these are not competing products; they serve different roles entirely. The MI300X is a data-center accelerator with no display outputs, no graphics API support, and a 750 W TDP. The RTX 4080 Mobile is a laptop GPU with a 110 W TDP, full graphics API support, and ray tracing hardware.

On raw compute, the MI300X dominates. Its Geekbench OpenCL score is 99.3% higher than the RTX 4080 Mobile. Its memory bandwidth is 5.32 TB/s versus 432.0 GB/s. Its FP32 throughput is 81.72 TFLOPS versus 24.72 TFLOPS. Any compute-heavy workload that fits in the MI300X's 192 GB HBM3 will run far faster on the AMD part.

The RTX 4080 Mobile wins on practicality for client workloads. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, meaning it can actually render graphics. It has RT cores and tensor cores for ray tracing and AI inference. It fits in a laptop, consumes 110 W, and uses a standard PCIe 4.0 x16 interface. None of that applies to the MI300X.

The verdict from the database is clear: choose the MI300X for server-side compute and AI training where massive memory and bandwidth matter. Choose the RTX 4080 Mobile for any task requiring a display output, rasterization, or conventional graphics APIs.

Specification Differences

| Field | AMD Instinct MI300X | NVIDIA GeForce RTX 4080 Mobile |

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

| Architecture | CDNA 3.0 | Ada Lovelace |

| Die Size | 1017 mm² | 294 mm² |

| Transistors | 153,000 million | 35,800 million |

| Transistor Density | 150.4M / mm² | 121.8M / mm² |

| Base Clock | 1000 MHz | 1290 MHz |

| Boost Clock | 2100 MHz | 1665 MHz |

| Memory Size | 192 GB | 12 GB |

| Memory Type | HBM3 | GDDR6 |

| Memory Bus | 8192 bit | 192 bit |

| Memory Bandwidth | 5.32 TB/s | 432.0 GB/s |

| Shading Units | 19,456 | 7,424 |

| TMUs | 1,216 | 232 |

| ROPs | 0 | 80 |

| RT Cores | None | 58 |

| Tensor Cores | None | 232 |

| Pixel Rate | 0 MPixel/s | 133.2 GPixel/s |

| Texture Rate | 2,553.6 GTexel/s | 386.3 GTexel/s |

| FP32 | 81.72 TFLOPS | 24.72 TFLOPS |

| FP16 | 81.72 TFLOPS (1:1) | 24.72 TFLOPS (1:1) |

| TDP | 750 W | 110 W |

| Slot Width | OAM Module | IGP |

| Bus Interface | PCIe 5.0 x16 | PCIe 4.0 x16 |

| Display Outputs | No outputs | Portable Device Dependent |

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

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.4 |

| Suggested PSU | 1150 W | None |

| Release Date | 2023-12-05 | 2023-01-02 |

| Production Status | Not listed | Active |

| Predecessor | Radeon Instinct | GeForce 30 Mobile |

| Successor | None | GeForce 50 Mobile |

FAQ

Q: Which GPU has the higher Geekbench OpenCL score?

A: The AMD Instinct MI300X scores 317,994, which is 99.3% higher than the RTX 4080 Mobile's 159,575.

Q: How much memory does each card have?

A: The MI300X has 192 GB of HBM3, while the RTX 4080 Mobile has 12 GB of GDDR6.

Q: Can the MI300X render graphics?

A: No. It has no display outputs, lists no DirectX, OpenGL, or Vulkan support, and has a pixel rate of 0 MPixel/s.

Q: What is the TDP difference?

A: The MI300X has a 750 W TDP, while the RTX 4080 Mobile has a 110 W TDP.

Q: Does the RTX 4080 Mobile support ray tracing?

A: Yes, it has 58 RT cores and 232 tensor cores, which enable hardware ray tracing and AI acceleration.

Q: How does the MI300X compare to other data-center GPUs?

A: It is 7.5% faster than the NVIDIA L40S and 10.7% faster than the NVIDIA RTX 6000 Ada Generation, but 5% slower than the NVIDIA H200 NVL and 8% slower than the NVIDIA B200.

Where Each One Wins

The AMD Instinct MI300X wins decisively in compute throughput. Its Geekbench OpenCL score of 317,994 is nearly double that of the RTX 4080 Mobile. Its memory subsystem is in a different class: 192 GB at 5.32 TB/s versus 12 GB at 432.0 GB/s. That combination suits large model inference, training datasets, and scientific computing where data residency and bandwidth are the limiting factors. Its FP32 and FP16 throughput of 81.72 TFLOPS is 3.3x the RTX 4080 Mobile's 24.72 TFLOPS. For workloads that can utilize its 8192-bit bus and HBM3 stack, the MI300X is the clear choice.

The RTX 4080 Mobile wins in every client-facing category. It is a working graphics card with DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 support. It has a usable pixel rate of 133.2 GPixel/s and a texture rate of 386.3 GTexel/s, though both are far below the MI300X's texture rate of 2,553.6 GTexel/s. It has RT cores and tensor cores, enabling ray-traced games and AI features like DLSS. It consumes 110 W, making it suitable for laptops, versus the MI300X's 750 W and external power requirements. It also uses PCIe 4.0, which is more common in consumer platforms than PCIe 5.0.

The production status differs as well. The RTX 4080 Mobile is listed as Active, while the MI300X has no recorded production status. The RTX 4080 Mobile has a successor, the GeForce 50 Mobile, while the MI300X does not. Release dates are close: January 2023 for the RTX 4080 Mobile and December 2023 for the MI300X. The database shows a clear split: the MI300X is for compute servers, the RTX 4080 Mobile is for portable graphics. Each wins where it is designed to operate.