AMD Instinct MI308X vs NVIDIA N1X 48SM Comparison

The Verdict

The AMD Instinct MI308X and NVIDIA N1X 48SM target entirely different segments, and the recorded data makes that separation clear. The MI308X is a compute-optimized accelerator built around the CDNA 3.0 architecture, with 19,456 shading units, 192 GB of HBM3 memory, and a 5.32 TB/s memory bus. The N1X 48SM is a Blackwell 2.0 IGP with 6,144 shading units, 128 GB of LPDDR5X, and a 273.2 GB/s memory path. Benchmark results show no head-to-head wins for either part because the database has no recorded overlapping benchmark scores, but the specification data alone indicates the MI308X is designed for memory-bandwidth-bound compute workloads while the N1X 48SM is an integrated processor aimed at space-constrained systems. Users requiring massive memory capacity and texture throughput should select the MI308X. Users needing a compact IGP with display output and ray tracing support should select the N1X 48SM.

Architecture Differences

The MI308X uses the CDNA 3.0 architecture on the Aqua Vanjaram chip, fabricated by TSMC on a 5 nm process. The die measures 1017 mm² and contains 153,000 million transistors, resulting in a transistor density of 150.4M per mm². The N1X 48SM uses the Blackwell 2.0 architecture on the GB20B chip, also fabricated by TSMC on a 5 nm process, but with a die size of 382 mm² and an unknown transistor count. The MI308X has no display outputs, while the N1X 48SM includes a single HDMI output. The MI308X is an OAM module with no power connectors listed, and the N1X 48SM is an IGP with no power connectors. Both parts use a PCIe 5.0 x16 bus interface. The MI308X supports no graphics APIs (DirectX, OpenGL, Vulkan all listed as N/A), and the N1X 48SM also lists all graphics APIs as N/A, confirming neither is intended for conventional gaming or consumer graphics workloads.

The memory architectures differ fundamentally. The MI308X uses HBM3 with a 8192-bit bus width and delivers 5.32 TB/s of bandwidth. The N1X 48SM uses LPDDR5X with a 256-bit bus width and delivers 273.2 GB/s of bandwidth. The MI308X memory clock is 1300 MHz with 5.2 Gbps effective transfer, while the N1X 48SM memory clock is 1067 MHz with 8.5 Gbps effective transfer. The N1X 48SM achieves higher effective transfer per pin, but the MI308X total bandwidth is far larger due to the 32x wider bus.

Head-to-Head Benchmarks

The database records no head-to-head benchmark results between these two parts, and neither item has an average benchmark score above zero. Both parts sit at the 50th percentile among all GPUs in the database, but that percentile is based on incomplete benchmark data. Without recorded scores, the analysis must rely on the specification fields that are present.

The FP32 compute figures show the MI308X at 81.72 TFLOPS and the N1X 48SM at 28.83 TFLOPS. That is approximately 2.8x higher FP32 throughput for the MI308X. FP16 performance is identical to FP32 for both parts: 81.72 TFLOPS for the MI308X and 28.83 TFLOPS for the N1X 48SM, both at a 1:1 ratio. Texture rate follows the same pattern: the MI308X delivers 2,553.6 GTexel/s versus 900.9 GTexel/s for the N1X 48SM, roughly 2.8x higher. Pixel rate is recorded as 0 MPixel/s for the MI308X because it has no ROPs, while the N1X 48SM has 48 ROPs and delivers 112.6 GPixel/s. The MI308X has 1,216 TMUs against 384 for the N1X 48SM, and the N1X 48SM includes 48 ray tracing cores and 192 tensor cores, while the MI308X lists no RT cores and no tensor cores.

Clock behavior also differs. The MI308X base clock is 1000 MHz with a 2100 MHz boost. The N1X 48SM base clock is 741 MHz with a 2346 MHz boost. The N1X 48SM boosts higher, but the MI308X starts from a higher base and carries far more execution units. The boost delta is 1100 MHz for the MI308X versus 1605 MHz for the N1X 48SM.

Specification Differences

The following fields differ between the two parts in the recorded database:

• Chip: Aqua Vanjaram (MI308X) versus GB20B (N1X 48SM)
• Architecture: CDNA 3.0 (MI308X) versus Blackwell 2.0 (N1X 48SM)
• Generation: Instinct (MIx) (MI308X) versus Blackwell IGP (N1x) (N1X 48SM)
• Transistors: 153,000 million (MI308X) versus unknown (N1X 48SM)
• Die size: 1017 mm² (MI308X) versus 382 mm² (N1X 48SM)
• Transistor density: 150.4M / mm² (MI308X) versus not recorded (N1X 48SM)
• Base clock: 1000 MHz (MI308X) versus 741 MHz (N1X 48SM)
• Boost clock: 2100 MHz (MI308X) versus 2346 MHz (N1X 48SM)
• Memory clock: 1300 MHz 5.2 Gbps effective (MI308X) versus 1067 MHz 8.5 Gbps effective (N1X 48SM)
• Memory size: 192 GB (MI308X) versus 128 GB (N1X 48SM)
• Memory type: HBM3 (MI308X) versus LPDDR5X (N1X 48SM)
• Memory bus width: 8192 bit (MI308X) versus 256 bit (N1X 48SM)
• Memory bandwidth: 5.32 TB/s (MI308X) versus 273.2 GB/s (N1X 48SM)
• Shading units: 19,456 (MI308X) versus 6,144 (N1X 48SM)
• TMUs: 1,216 (MI308X) versus 384 (N1X 48SM)
• ROPs: 0 (MI308X) versus 48 (N1X 48SM)
• RT cores: not recorded (MI308X) versus 48 (N1X 48SM)
• Tensor cores: not recorded (MI308X) versus 192 (N1X 48SM)
• Pixel rate: 0 MPixel/s (MI308X) versus 112.6 GPixel/s (N1X 48SM)
• Texture rate: 2,553.6 GTexel/s (MI308X) versus 900.9 GTexel/s (N1X 48SM)
• FP32: 81.72 TFLOPS (MI308X) versus 28.83 TFLOPS (N1X 48SM)
• FP16: 81.72 TFLOPS (MI308X) versus 28.83 TFLOPS (N1X 48SM)
• TDP: 750 W (MI308X) versus unknown (N1X 48SM)
• Suggested PSU: 1150 W (MI308X) versus not recorded (N1X 48SM)
• Slot width: OAM Module (MI308X) versus IGP (N1X 48SM)
• Display outputs: No outputs (MI308X) versus 1x HDMI (N1X 48SM)
• Release date: 2023-12-05 (MI308X) versus 2026-05-31 (N1X 48SM)
• Production status: not recorded (MI308X) versus Active (N1X 48SM)
• Predecessor: Radeon Instinct (MI308X) versus not recorded (N1X 48SM)

Fields that are identical include the process node (5 nm), foundry (TSMC), power connectors (None), bus interface (PCIe 5.0 x16), and the API list (all N/A).

FAQ

Q: Which processor has higher FP32 compute performance?

A: The AMD Instinct MI308X records 81.72 TFLOPS FP32, which is 2.8x the 28.83 TFLOPS of the NVIDIA N1X 48SM.

Q: What memory capacity does each part support?

A: The MI308X has 192 GB of HBM3 on a 8192-bit bus with 5.32 TB/s bandwidth. The N1X 48SM has 128 GB of LPDDR5X on a 256-bit bus with 273.2 GB/s bandwidth.

Q: Does either part support display output?

A: No. The MI308X lists no display outputs, while the N1X 48SM includes a single HDMI output.

Q: Which part has ray tracing hardware?

A: The N1X 48SM includes 48 ray tracing cores and 192 tensor cores. The MI308X records no RT cores and no tensor cores.

Q: What is the boost clock difference?

A: The MI308X boosts to 2100 MHz from a 1000 MHz base. The N1X 48SM boosts to 2346 MHz from a 741 MHz base, giving it a higher peak clock but a lower base clock.

Q: Which part has a larger die?

A: The MI308X die measures 1017 mm² with 153,000 million transistors. The N1X 48SM die measures 382 mm² with an unknown transistor count.

Where Each One Wins

The AMD Instinct MI308X wins in raw compute throughput. Its 81.72 TFLOPS FP32 and FP16 figures exceed the N1X 48SM by roughly 2.8x. Texture rate is also far higher at 2,553.6 GTexel/s versus 900.9 GTexel/s. Memory bandwidth is the largest gap: 5.32 TB/s versus 273.2 GB/s, a 19.5x difference. The 192 GB capacity versus 128 GB gives the MI308X a 50% capacity advantage. The 8192-bit bus versus 256-bit bus confirms the MI308X is built for bandwidth-saturated workloads such as large model inference or data processing. The 750 W TDP and 1150 W suggested PSU indicate a power-hungry accelerator, but the data does not record a runtime power figure for the N1X 48SM.

The NVIDIA N1X 48SM wins in areas the MI308X does not address. It has 48 ROPs and a 112.6 GPixel/s pixel rate, while the MI308X records 0 ROPs and 0 MPixel/s. It includes 48 ray tracing cores and 192 tensor cores, both absent from the MI308X record. It provides a single HDMI output, the MI308X provides none. The boost clock is higher at 2346 MHz versus 2100 MHz, and the effective memory transfer rate is higher at 8.5 Gbps versus 5.2 Gbps, though the total bandwidth is far lower due to the narrower bus. The N1X 48SM is an IGP form factor, which fits systems where a discrete OAM module cannot be used. Its production status is Active, while the MI308X production status is not recorded.

For workload placement, the MI308X is the choice when the task demands maximum memory bandwidth, large capacity, and high FP32 or FP16 throughput. The N1X 48SM is the choice when the system requires a display output, ray tracing support, or tensor core acceleration, and when the physical footprint must be an integrated processor. The release dates place the MI308X in December 2023 and the N1X 48SM in May 2026, so the N1X 48SM is the newer part by the recorded timeline. Neither part has benchmark scores in the database, so any performance ranking beyond the specification fields cannot be derived from the recorded data. The percentile rating of 50 for both parts is not based on measured scores and should not be used for direct comparison.