AMD Instinct MI300X vs AMD Instinct MI355X Comparison

# AMD Instinct MI300X vs AMD Instinct MI355X

The AMD Instinct MI300X and AMD Instinct MI355X represent two successive generations of AMD's data center accelerator lineup, built on CDNA 3.0 and CDNA 4.0 architectures respectively. The MI300X has recorded benchmark data, while the MI355X currently has no benchmark scores in the database. This analysis relies on the available measurements and architectural specifications to compare the two.

Where Each One Wins

The MI300X is the only one of the two with recorded benchmark data. Its Geekbench OpenCL score of 317,994 places it at the 100th percentile of all GPUs in the database. This means the MI300X sits at the top of the recorded performance distribution, ahead of every other GPU in the database according to this single metric.

The MI355X, by contrast, has no benchmark entries. Its percentile rank is 50, which reflects the absence of measured data rather than a performance assessment. With an average benchmark score of 0 and no nearest rivals listed, the MI355X cannot be positioned relative to any other accelerator in the database.

In terms of raw compute metrics, the MI300X delivers 81.72 TFLOPS of FP32 and 81.72 TFLOPS of FP16 (1:1 ratio). The MI355X delivers 78.64 TFLOPS of FP32 and 78.64 TFLOPS of FP16 (1:1 ratio). The MI300X leads in both FP32 and FP16 throughput by a margin of 3.08 TFLOPS, which corresponds to roughly 3.9% higher compute throughput in each precision format.

The MI355X wins in memory capacity and bandwidth. It carries 288 GB of HBM3e memory versus 192 GB of HBM3 on the MI300X, a 96 GB advantage. Its memory bandwidth is 8.19 TB/s compared to 5.32 TB/s, an advantage of 2.87 TB/s. The MI355X memory clock runs at 2000 MHz with 8 Gbps effective data rate, while the MI300X memory runs at 1300 MHz with 5.2 Gbps effective.

Architecture Differences

The two accelerators use different chip designs and process nodes. The MI300X uses the Aqua Vanjaram chip built on CDNA 3.0 architecture at a 5 nm process node from TSMC. The MI355X uses the MI350 256CU chip built on CDNA 4.0 architecture at a 3 nm process node, also from TSMC.

Transistor counts differ substantially. The MI300X contains 153,000 million transistors on a 1017 mm² die, yielding a transistor density of 150.4 million transistors per square millimeter. The MI355X contains 185,000 million transistors on a 2380 mm² die, yielding a density of 77.7 million transistors per square millimeter. The MI355X has 32,000 million more transistors, but its die is 1363 mm² larger, which explains the lower density figure.

Shader core counts differ. The MI300X has 19,456 shading units and 1,216 texture mapping units. The MI355X has 16,384 shading units and 1,024 texture mapping units. The MI300X therefore has 3,072 more shading units and 192 more TMUs. Neither accelerator has ROPs, as both report 0 MPixel/s pixel rate.

Texture rate numbers reflect the core count differences. The MI300X achieves 2,553.6 GTexel/s, while the MI355X achieves 2,457.6 GTexel/s. The MI300X leads by 96 GTexel/s.

Boost clocks differ. The MI300X boosts to 2100 MHz, while the MI355X boosts to 2400 MHz. Both have a 1000 MHz base clock. The MI355X's 300 MHz higher boost clock partially compensates for its lower core count, but the MI300X still holds the compute throughput lead.

Both use the PCIe 5.0 x16 bus interface and come as OAM Module form factors. Neither has display outputs, and both have no power connectors on the board. The MI300X has a 750 W TDP and a suggested PSU of 1150 W. The MI355X has a 1400 W TDP and a suggested PSU of 1800 W. The MI355X consumes 650 W more at TDP and requires a 650 W larger suggested power supply.

Head-to-Head Benchmarks

The database contains no head-to-head benchmark entries for these two accelerators. The headToHeadBenchmarks field is empty, and the win counts for both items are 0. Consequently, all performance comparisons must come from the separate benchmark record of the MI300X and the architectural specifications of both.

The MI300X's Geekbench OpenCL score of 317,994 can be compared to its nearest rivals. The NVIDIA H200 NVL scores 334,891, which is 5% higher than the MI300X. The NVIDIA B200 scores 345,482, which is 8% higher. The MI300X beats the NVIDIA L40S, which scores 295,763, by 7.5%. It also beats the NVIDIA RTX 6000 Ada Generation, which scores 287,237, by 10.7%.

These rival comparisons show the MI300X's position in the broader accelerator landscape. It trails the H200 NVL and B200 by 5% and 8% respectively, while leading the L40S and RTX 6000 Ada Generation by 7.5% and 10.7%. The MI300X's 100th percentile rank indicates it is at the maximum recorded position in the database distribution.

The MI355X has no comparable data. Its lack of benchmark scores means no delta percentages or rival positions can be calculated. The architectural metrics provide the only quantitative comparison. In FP32 throughput, the MI300X delivers 81.72 TFLOPS against the MI355X's 78.64 TFLOPS. In memory bandwidth, the MI355X delivers 8.19 TB/s against the MI300X's 5.32 TB/s. These two metrics capture the fundamental trade-off between the two designs: the MI300X emphasizes compute throughput, while the MI355X emphasizes memory capacity and bandwidth.

FAQ

Q: Which accelerator has a higher recorded benchmark score?

A: The MI300X has a Geekbench OpenCL score of 317,994. The MI355X has no recorded benchmark scores in the database.

Q: How does the MI300X compare to its nearest rivals?

A: The MI300X is 5% behind the NVIDIA H200 NVL, 8% behind the NVIDIA B200, 7.5% ahead of the NVIDIA L40S, and 10.7% ahead of the NVIDIA RTX 6000 Ada Generation.

Q: Which accelerator has more memory and bandwidth?

A: The MI355X has 288 GB of HBM3e memory with 8.19 TB/s bandwidth. The MI300X has 192 GB of HBM3 memory with 5.32 TB/s bandwidth.

Q: Which accelerator has higher FP32 and FP16 compute throughput?

A: The MI300X delivers 81.72 TFLOPS in both FP32 and FP16 (1:1). The MI355X delivers 78.64 TFLOPS in both FP32 and FP16 (1:1).

Q: What are the physical differences between the two chips?

A: The MI300X uses a 5 nm process with 153,000 million transistors on a 1017 mm² die. The MI355X uses a 3 nm process with 185,000 million transistors on a 2380 mm² die.

Q: What is the power requirement difference?

A: The MI300X has a 750 W TDP and a suggested PSU of 1150 W. The MI355X has a 1400 W TDP and a suggested PSU of 1800 W.

The Verdict

The data supports a clear split between the two accelerators. For workloads that depend on compute throughput, the MI300X delivers higher FP32 and FP16 figures, with 81.72 TFLOPS in both formats against 78.64 TFLOPS for the MI355X. It also has a recorded benchmark score of 317,994 at the 100th percentile, which places it at the top of the database distribution.

For workloads that depend on memory capacity and bandwidth, the MI355X is the stronger design. Its 288 GB of HBM3e memory exceeds the MI300X's 192 GB by 96 GB, and its 8.19 TB/s bandwidth exceeds the MI300X's 5.32 TB/s by 2.87 TB/s. The newer 3 nm process node and 2400 MHz boost clock also point to a more advanced design.

The MI355X's lack of benchmark data means its real-world performance cannot be verified from the database. The MI300X has demonstrated performance at the 100th percentile against all GPUs, while the MI355X sits at the 50th percentile solely because it has no measurements. Users who require verified performance should look to the MI300X. Users who require maximum memory capacity and bandwidth should consider the MI355X, provided they can accommodate its 1400 W TDP and 1800 W suggested PSU.

Specification Differences

| Specification | AMD Instinct MI300X | AMD Instinct MI355X |

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

| Chip | Aqua Vanjaram | MI350 256CU |

| Architecture | CDNA 3.0 | CDNA 4.0 |

| Process Node | 5 nm | 3 nm |

| Transistors | 153,000 million | 185,000 million |

| Die Size | 1017 mm² | 2380 mm² |

| Boost Clock | 2100 MHz | 2400 MHz |

| Memory Size | 192 GB | 288 GB |

| Memory Type | HBM3 | HBM3e |

| Memory Clock | 1300 MHz 5.2 Gbps effective | 2000 MHz 8 Gbps effective |

| Memory Bandwidth | 5.32 TB/s | 8.19 TB/s |

| Shading Units | 19456 | 16384 |

| TMUs | 1216 | 1024 |

| Texture Rate | 2,553.6 GTexel/s | 2,457.6 GTexel/s |

| FP32 | 81.72 TFLOPS | 78.64 TFLOPS |

| FP16 | 81.72 TFLOPS (1:1) | 78.64 TFLOPS (1:1) |

| TDP | 750 W | 1400 W |

| Suggested PSU | 1150 W | 1800 W |

| Release Date | 2023-12-05 | 2025-06-11 |

| Dimensions | Not listed | 102 mm length, 165 mm width |