AMD Instinct MI300 vs AMD Radeon Instinct MI300A Comparison

FAQ

Q: What are the core architectural similarities between the AMD Instinct MI300 and the AMD Radeon Instinct MI300A?

A: Both GPUs are built on the CDNA 3.0 architecture and use the same Aqua Vanjaram chip. Both are manufactured on a 5 nm process at TSMC, with 153,000 million transistors on a 1017 mm² die, giving a transistor density of 150.4M / mm².

Q: How do the two accelerators differ in memory capacity and bandwidth?

A: The MI300 offers 128 GB of HBM3 memory with 5.32 TB/s bandwidth, while the MI300A provides 192 GB of HBM3 memory with 10.3 TB/s bandwidth. Both use an 8192 bit bus width.

Q: What is the difference in boost clock between the two cards?

A: The MI300 has a boost clock of 1700 MHz, while the MI300A boosts to 2100 MHz. Both share the same 1000 MHz base clock.

Q: Which model delivers higher FP32 and FP16 compute throughput?

A: The MI300A is substantially higher in both metrics. It delivers 81.72 TFLOPS FP32 versus 47.87 TFLOPS for the MI300, and 653.7 TFLOPS FP16 (8:1) versus 47.87 TFLOPS FP16 (1:1) for the MI300.

Q: Are there differences in power requirements and physical form?

A: Yes. The MI300 has a TDP of 600 W with a suggested PSU of 1000 W and uses 2x 8-pin power connectors. The MI300A has a TDP of 750 W with a suggested PSU of 1150 W, uses no power connectors, and is an OAM Module. The MI300 is a 267 mm (10.5 inches) long, 111 mm (4.4 inches) high card.

Q: Do both cards support standard graphics APIs?

A: The MI300 lists DirectX, OpenGL, and Vulkan as N/A. The MI300A has null values for these APIs. Neither card has display outputs.

Architecture Differences

Both accelerators share the same fundamental silicon: the Aqua Vanjaram chip fabricated by TSMC on a 5 nm node. The transistor count is identical at 153,000 million, and the die size is the same at 1017 mm². The architectural base is CDNA 3.0 for both, so the instruction set and compute model are consistent across the two products.

The differences appear in how the silicon is configured and clocked. The MI300A runs a higher boost clock at 2100 MHz compared to the MI300's 1700 MHz, while both maintain a 1000 MHz base clock. This clock advantage contributes directly to the MI300A's higher compute throughput.

Shader resource allocation differs significantly. The MI300A packs 19,456 shading units and 1,216 TMUs, while the MI300 has 14,080 shading units and 880 TMUs. Texture rate scales accordingly: the MI300A reaches 2,553.6 GTexel/s versus 1,496.0 GTexel/s for the MI300. Both cards have zero ROPs and a pixel rate of 0 MPixel/s, confirming their compute-only orientation.

Memory architecture diverges on capacity and speed. The MI300A carries 192 GB of HBM3 versus 128 GB on the MI300, and its memory clock runs at 2525 MHz (10.1 Gbps effective) versus 1300 MHz (5.2 Gbps effective) on the MI300. Bandwidth jumps from 5.32 TB/s to 10.3 TB/s, a near doubling. Both use an 8192 bit memory bus.

FP16 processing reveals a major architectural difference. The MI300 executes FP16 at 47.87 TFLOPS with a 1:1 ratio to FP32, meaning it does not use a specialized tensor-style path. The MI300A executes FP16 at 653.7 TFLOPS with an 8:1 ratio to FP32, indicating a dedicated matrix engine that accelerates FP16 workloads far beyond the standard shader rate.

Power delivery and physical format also differ. The MI300 is a 600 W card with 2x 8-pin power connectors and a 1000 W suggested PSU, measuring 267 mm by 111 mm. The MI300A is a 750 W OAM Module with no power connectors and a 1150 W suggested PSU, designed for board-level integration rather than PCIe slot mounting. Both connect via PCIe 5.0 x16 and have no display outputs.

Where Each One Wins

The MI300A wins decisively in raw compute density. Its FP32 throughput of 81.72 TFLOPS is 70% higher than the MI300's 47.87 TFLOPS. FP16 workloads favor the MI300A even more strongly, with 653.7 TFLOPS versus 47.87 TFLOPS, a 12.7x advantage. Any workload that stresses peak FLOPs, such as large matrix operations or dense neural network training, will prefer the MI300A.

Memory-bound applications also favor the MI300A. Its 10.3 TB/s bandwidth is 94% higher than the MI300's 5.32 TB/s, and the 192 GB capacity is 50% larger. Workloads that stream large datasets, such as training sets or simulation grids, will see meaningful gains from the extra bandwidth and capacity.

The MI300's advantages are narrower. It uses a standard PCIe card form factor with 2x 8-pin power connectors, making it easier to integrate into conventional server chassis. Its 600 W TDP and 1000 W suggested PSU place lower demands on power delivery than the MI300A's 750 W TDP and 1150 W suggested PSU. The MI300 also carries a standard 267 mm length and 111 mm height, while the MI300A is an OAM Module with no listed dimensions.

For FP16 work where precision is critical, the MI300's 1:1 FP16 to FP32 ratio may be preferable. The MI300A's 8:1 ratio means its FP16 throughput is achieved through a different execution path, which may not suit all algorithms. The MI300 delivers identical FP16 and FP32 rates, a simpler model for mixed-precision code that expects a uniform throughput profile.

Specification Differences

| Specification | AMD Instinct MI300 | AMD Radeon Instinct MI300A |

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

| Boost clock | 1700 MHz | 2100 MHz |

| Memory size | 128 GB | 192 GB |

| Memory clock | 1300 MHz 5.2 Gbps effective | 2525 MHz 10.1 Gbps effective |

| Bandwidth | 5.32 TB/s | 10.3 TB/s |

| Shading units | 14,080 | 19,456 |

| TMUs | 880 | 1,216 |

| Texture rate | 1,496.0 GTexel/s | 2,553.6 GTexel/s |

| FP32 | 47.87 TFLOPS | 81.72 TFLOPS |

| FP16 | 47.87 TFLOPS (1:1) | 653.7 TFLOPS (8:1) |

| TDP | 600 W | 750 W |

| Power connectors | 2x 8-pin | None |

| Suggested PSU | 1000 W | 1150 W |

| Slot width | Not listed | OAM Module |

| Dimensions | 267 mm x 111 mm | Not listed |

| Release date | 2023-01-03 | 2023-12-05 |

| Predecessor | Radeon Instinct | FirePro Data Center |

Fields that are identical include the base clock at 1000 MHz, memory type HBM3, bus width at 8192 bit, transistor count at 153,000 million, die size at 1017 mm², process node at 5 nm, foundry at TSMC, architecture CDNA 3.0, chip Aqua Vanjaram, bus interface PCIe 5.0 x16, and display outputs as none. Both cards have no ROPs, a 0 MPixel/s pixel rate, no RT cores, no tensor cores listed, and no launch MSRP recorded. Neither has benchmark scores in the database, and both sit at the 50th percentile against all GPUs.

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark runs for these two accelerators, and neither card has individual benchmark scores recorded. The comparison below is derived solely from the specifications in the database.

FP32 throughput is the clearest differentiator. The MI300A delivers 81.72 TFLOPS, which is 33.85 TFLOPS higher than the MI300's 47.87 TFLOPS. In percentage terms, the MI300A is 70.7% faster in FP32, a substantial margin for any compute workload that uses single-precision floating point.

FP16 shows an even larger gap. The MI300A's 653.7 TFLOPS is 605.83 TFLOPS higher than the MI300's 47.87 TFLOPS, a 12.7x difference. This is the largest specification delta between the two cards and indicates a fundamentally different approach to reduced-precision compute. The MI300A's 8:1 FP16 to FP32 ratio shows it has specialized matrix hardware, while the MI300's 1:1 ratio means it processes FP16 at the same rate as FP32.

Memory bandwidth follows a similar pattern. The MI300A's 10.3 TB/s is 4.98 TB/s higher than the MI300's 5.32 TB/s, a 93.6% increase. Combined with the 192 GB versus 128 GB capacity difference, the MI300A can feed its larger compute throughput with significantly more data per second.

Texture rate scales with the shader and TMU counts. The MI300A reaches 2,553.6 GTexel/s versus 1,496.0 GTexel/s for the MI300, a 70.7% advantage that mirrors the FP32 and shader unit deltas. This consistency suggests the MI300A is not just clocking higher, it is using a fuller configuration of the same chip.

Power efficiency is the one area where the MI300 looks better. The MI300 delivers 47.87 TFLOPS at 600 W, or 79.8 GFLOPS per watt. The MI300A delivers 81.72 TFLOPS at 750 W, or 109.0 GFLOPS per watt. In FP32, the MI300A is actually more efficient despite the higher TDP. The MI300 draws 150 W less total power and requires a 150 W smaller suggested PSU, which matters for dense server deployments with strict power budgets.

The Verdict

The data points to a clear performance hierarchy. The MI300A is the stronger accelerator in every compute and memory metric: 70.7% higher FP32, 12.7x higher FP16, 93.6% higher bandwidth, and 50% more memory capacity. It also reaches a higher boost clock at 2100 MHz versus 1700 MHz, and it uses more of the Aqua Vanjaram chip's resources with 19,456 shading units versus 14,080.

The MI300 occupies a distinct position. It is a 600 W PCIe card with standard 2x 8-pin power connectors and a conventional 267 mm by 111 mm footprint. The MI300A is an OAM Module with no power connectors and a 750 W TDP, which requires a different server platform. Systems that can accommodate the OAM form factor and 1150 W PSU guidance will get substantially more compute and memory throughput from the MI300A.

For FP16 workloads, the choice depends on the execution model. The MI300A's 653.7 TFLOPS at 8:1 ratio is far higher, but the MI300's 47.87 TFLOPS at 1:1 ratio offers uniform FP16 and FP32 performance. Algorithms that rely on consistent throughput across precisions may prefer the MI300's simpler profile.

The release timeline also differs. The MI300 launched on 2023-01-03 with a Radeon Instinct predecessor, while the MI300A launched on 2023-12-05 with a FirePro Data Center predecessor. The later release date for the MI300A aligns with its more advanced configuration.

Both cards sit at the 50th percentile against all GPUs in the database, and neither has recorded benchmark scores or nearest rivals. The specification deltas, however, are unambiguous. The MI300A is the higher-performance part for compute-heavy and memory-heavy workloads. The MI300 is the lower-power, standard-form-factor option for systems that cannot support an OAM module.