AMD Instinct MI300 vs NVIDIA GeForce RTX 4080 Mobile Comparison

FAQ

Q: What are the core architectural identities of the AMD Instinct MI300 and the NVIDIA GeForce RTX 4080 Mobile?

A: The MI300 is built on the CDNA 3.0 architecture using the Aqua Vanjaram chip, while the RTX 4080 Mobile uses the Ada Lovelace architecture with the AD104 chip. Both are manufactured on a 5 nm process at TSMC.

Q: How do the memory subsystems compare between the two?

A: The MI300 carries 128 GB of HBM3 on an 8192-bit bus, delivering 5.32 TB/s of bandwidth. The RTX 4080 Mobile has 12 GB of GDDR6 on a 192-bit bus, providing 432.0 GB/s. The MI300 has a memory clock of 1300 MHz (5.2 Gbps effective), while the RTX 4080 Mobile runs its memory at 2250 MHz (18 Gbps effective).

Q: Which device has higher raw compute throughput?

A: The MI300 delivers 47.87 TFLOPS in both FP32 and FP16 (1:1), while the RTX 4080 Mobile delivers 24.72 TFLOPS in both formats. The MI300 also has a texture rate of 1,496.0 GTexel/s versus 386.3 GTexel/s for the RTX 4080 Mobile.

Q: What are the power requirements for each unit?

A: The MI300 has a TDP of 600 W and requires a 1000 W suggested PSU with 2x 8-pin power connectors. The RTX 4080 Mobile has a 110 W TDP, is classified as an IGP, and uses no power connectors.

Q: What is the physical size of the MI300?

A: The MI300 measures 267 mm (10.5 inches) in length and 111 mm (4.4 inches) in height. It has a die size of 1017 mm² and contains 153,000 million transistors. The RTX 4080 Mobile has no listed dimensions, with a die size of 294 mm² and 35,800 million transistors.

Q: What benchmark data exists for each product?

A: The RTX 4080 Mobile has recorded scores including 159,575 in Geekbench OpenCL, 145,807 in Geekbench Vulkan, and 24,926 in Passmark G3D, with an average benchmark score of 38,135. The MI300 has no recorded benchmark scores and sits at the 50th percentile versus all GPUs, while the RTX 4080 Mobile sits at the 81st percentile.

Where Each One Wins

The recorded data splits the two accelerators into separate domains. The AMD Instinct MI300 wins decisively on every compute and memory throughput metric. Its FP32 throughput of 47.87 TFLOPS is 93.6% higher than the RTX 4080 Mobile's 24.72 TFLOPS. Memory bandwidth tells a similar story: 5.32 TB/s versus 432.0 GB/s, a 12.3x advantage for the MI300. Texture rate also favors AMD, at 1,496.0 GTexel/s versus 386.3 GTexel/s. These are datacenter-scale specifications designed for massive parallel workloads.

The NVIDIA GeForce RTX 4080 Mobile wins in areas the MI300 does not address. The MI300 has zero ROPs and a pixel rate of 0 MPixel/s, with no display outputs. The RTX 4080 Mobile delivers 133.2 GPixel/s and includes 80 ROPs, making it the only one of the two capable of producing rendered frames for display. The RTX 4080 Mobile also brings dedicated ray tracing cores (58) and tensor cores (232), features entirely absent from the MI300's specification sheet. Its API support is complete: DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, whereas the MI300 lists N/A for all three.

The RTX 4080 Mobile is the only one with measurable benchmark results. Its average benchmark score of 38,135 places it at the 81st percentile, and it sits within a tight competitive cluster: the NVIDIA GeForce MX570 scores 38,299 (0.4% lower), the RTX 5080 Mobile scores 38,349 (0.6% lower), the RTX 4070 scores 37,648 (1.3% higher), and the Tesla P4 scores 37,628 (1.3% higher). The MI300 has no recorded benchmark scores, meaning the database contains no direct performance measurements for it.

Architecture Differences

The two chips represent fundamentally different design philosophies. The MI300 uses CDNA 3.0, AMD's compute-optimized architecture aimed at accelerators, while the RTX 4080 Mobile uses Ada Lovelace, a graphics-first architecture with full rendering capabilities. The MI300's chip is Aqua Vanjaram, a massive 1017 mm² die fabricated at TSMC with 153,000 million transistors, achieving a transistor density of 150.4M / mm². The RTX 4080 Mobile's AD104 die is 294 mm² with 35,800 million transistors, a density of 121.8M / mm².

The MI300 has 14,080 shading units and 880 TMUs, but zero ROPs and zero RT cores. It has no tensor core count listed. Its pixel rate is 0 MPixel/s, confirming it is not designed for rasterization output. The RTX 4080 Mobile has 7,424 shading units, 232 TMUs, 80 ROPs, 58 RT cores, and 232 tensor cores. Its pixel rate is 133.2 GPixel/s.

API support separates them completely. The MI300 lists DirectX, OpenGL, and Vulkan as N/A, indicating no consumer graphics API path. The RTX 4080 Mobile supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI300 uses a PCIe 5.0 x16 interface, while the RTX 4080 Mobile uses PCIe 4.0 x16.

The MI300 has no display outputs; the RTX 4080 Mobile's outputs are listed as "Portable Device Dependent." The power delivery also differs sharply: the MI300 requires 2x 8-pin connectors and a 1000 W PSU, while the RTX 4080 Mobile uses none.

Specification Differences

The process node is identical (5 nm, TSMC), but nearly every other specification diverges. The MI300 has 153,000 million transistors versus 35,800 million; a die size of 1017 mm² versus 294 mm²; and a transistor density of 150.4M / mm² versus 121.8M / mm². Base clocks are 1000 MHz for the MI300 and 1290 MHz for the RTX 4080 Mobile, while boost clocks are 1700 MHz and 1665 MHz respectively.

Memory capacity differs by more than an order of magnitude: 128 GB of HBM3 versus 12 GB of GDDR6. Bus widths are 8192-bit versus 192-bit, and bandwidth is 5.32 TB/s versus 432.0 GB/s. The MI300's memory clock is 1300 MHz (5.2 Gbps effective), while the RTX 4080 Mobile's is 2250 MHz (18 Gbps effective).

Compute resources: 14,080 shading units versus 7,424, 880 TMUs versus 232, 0 ROPs versus 80. The MI300 has no RT cores; the RTX 4080 Mobile has 58. The MI300 has no tensor cores listed; the RTX 4080 Mobile has 232. Pixel rate is 0 MPixel/s versus 133.2 GPixel/s, and texture rate is 1,496.0 GTexel/s versus 386.3 GTexel/s. FP32 and FP16 are each 47.87 TFLOPS for the MI300 versus 24.72 TFLOPS for the RTX 4080 Mobile.

TDP is 600 W versus 110 W. The MI300 uses 2x 8-pin power connectors, the RTX 4080 Mobile uses none. The MI300 has a suggested PSU of 1000 W; the RTX 4080 Mobile has none listed. The MI300's bus interface is PCIe 5.0 x16 versus PCIe 4.0 x16. The MI300 presents no display outputs; the RTX 4080 Mobile is "Portable Device Dependent."

The MI300 measures 267 mm by 111 mm; the RTX 4080 Mobile has no listed dimensions and is classified as IGP slot width. The MI300's production status is unlisted, while the RTX 4080 Mobile is Active. The RTX 4080 Mobile has a successor (GeForce 50 Mobile); the MI300 does not. The MI300's predecessor is Radeon Instinct; the RTX 4080 Mobile's is GeForce 30 Mobile.

Head-to-Head Benchmarks

The database contains no head-to-head benchmark entries for these two products, and the MI300 has no individual benchmark scores. All quantitative comparisons must come from the specification sheet and the RTX 4080 Mobile's recorded results.

The largest wins for the MI300 are in throughput. Its FP32 output of 47.87 TFLOPS is 1.94x the RTX 4080 Mobile's 24.72 TFLOPS. Memory bandwidth is the widest gap: 5.32 TB/s versus 432.0 GB/s, a 12.3x difference. Texture rate favors the MI300 by 3.87x, at 1,496.0 GTexel/s versus 386.3 GTexel/s. Transistor count is 4.27x higher, and die size is 3.46x larger.

The RTX 4080 Mobile's wins are in rendering and measured performance. It produces 133.2 GPixel/s while the MI300 produces none. It has 80 ROPs against zero. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, all of which are N/A on the MI300. Its base clock is 290 MHz higher, and its memory clock is 950 MHz higher (2250 MHz versus 1300 MHz).

On recorded benchmarks, the RTX 4080 Mobile scores 159,575 in Geekbench OpenCL, 145,807 in Geekbench Vulkan, 24,926 in Passmark G3D, 11,191 in Passmark GPU Compute, 929 in Passmark G2D, 286 in Passmark DirectX 9, 244 in Passmark DirectX 11, 157 in Passmark DirectX 10, and 96 in Passmark DirectX 12. Its average benchmark score is 38,135, placing it at the 81st percentile. The MI300 sits at the 50th percentile with an average benchmark score of 0.

The RTX 4080 Mobile's nearest rivals in the database all sit within a narrow band. The MX570 trails by 0.4%, the RTX 5080 Mobile trails by 0.6%, the RTX 4070 leads by 1.3%, and the Tesla P4 leads by 1.3%. This clustering indicates that the RTX 4080 Mobile's measured performance is tightly grouped with other mid-range options in the database, despite its high specification count.

The Verdict

The data describes two products with almost no functional overlap. The AMD Instinct MI300 is a compute accelerator: no display outputs, no ROPs, no graphics APIs, and a 600 W power envelope. Its specifications target massive parallel throughput, with 128 GB of HBM3, 5.32 TB/s of bandwidth, and 47.87 TFLOPS of FP32. It is built for workloads that scale across a 8192-bit memory bus and a 1017 mm² die.

The NVIDIA GeForce RTX 4080 Mobile is a graphics processor for portable devices. It has a 110 W TDP, no power connectors, IGP slot width, and display outputs dependent on the host device. It delivers 133.2 GPixel/s, supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, and includes ray tracing and tensor cores. Its measured benchmark scores place it at the 81st percentile, with an average score of 38,135.

For rendering, display output, and mobile integration, the RTX 4080 Mobile is the only viable option in this comparison. For raw compute throughput, memory capacity, and memory bandwidth, the MI300 dominates every recorded metric. The MI300 has no benchmark scores in the database, so its percentile rank of 50 and average score of 0 reflect an absence of measurements rather than a performance deficiency. The RTX 4080 Mobile's percentile of 81 is backed by nine recorded benchmark results.

The choice depends entirely on workload. Data-heavy compute tasks align with the MI300's 128 GB HBM3 pool and 5.32 TB/s bandwidth. Graphics workloads, including ray tracing and standard API rendering, align with the RTX 4080 Mobile's 58 RT cores, 232 tensor cores, and complete API support. The MI300's 600 W TDP and 1000 W suggested PSU indicate a fixed installation, while the RTX 4080 Mobile's 110 W TDP and connector-free design suit mobile platforms. The recorded data supports no other conclusion.