AMD Instinct MI300A vs NVIDIA B300 SXM6 AC Comparison

The Verdict

The recorded data presents a clear performance hierarchy between these two accelerators, though the comparison is limited by the available measurements. The NVIDIA B300 SXM6 AC holds the only benchmark score in the database, a Geekbench OpenCL result of 369,831 points, placing it at the 100th percentile of all GPUs. The AMD Instinct MI300A has no recorded benchmark scores and sits at the 50th percentile, meaning the database contains no direct performance measurements for it.

The NVIDIA B300 SXM6 AC is the choice for workloads that demand peak measured compute performance, as its single recorded score demonstrates leadership against its nearest rivals. It outperforms the NVIDIA B200 by 7%, the NVIDIA H200 NVL by 10.4%, the AMD Instinct MI300X by 16.3%, and the NVIDIA L40S by 25%. These margins indicate a substantial generational step within NVIDIA's own lineup and a clear advantage over the closest AMD competitor that has recorded data.

The AMD Instinct MI300A, with no benchmark entries, cannot be positioned relative to the B300 based on measured results. Its architecture and specifications suggest a different design philosophy, but the database lacks the evidence to declare it a winner in any measured category. Buyers who require verified performance data should select the B300 SXM6 AC. Those considering the MI300A must rely on its architectural characteristics, as no benchmark evidence exists in the database to validate its performance claims.

Architecture Differences

The two accelerators come from different design lineages. AMD's Instinct MI300A uses the Aqua Vanjaram chip built on the CDNA 3.0 architecture, part of the Instinct (MIx) generation. NVIDIA's B300 SXM6 AC uses the GB110 chip built on the Blackwell Ultra architecture, part of the Server Blackwell (Bxx) generation. Both are manufactured by TSMC on a 5 nm process, but their transistor budgets differ significantly.

The B300 packs 208,000 million transistors on a 1628 mm² die, while the MI300A contains 153,000 million transistors on a 1017 mm² die. This gives the MI300A a higher transistor density at 150.4 million per mm² compared to the B300's 127.8 million per mm². Despite the smaller die, AMD achieves tighter packing, while NVIDIA uses its larger die area for a greater absolute transistor count.

Clock behavior differs substantially. The B300 runs a base clock of 1665 MHz and a boost clock of 2032 MHz. The MI300A operates at a much lower base of 1000 MHz with a boost of 2100 MHz, meaning the AMD part has a wider clock range and a slightly higher peak boost, but a far lower idle floor.

Memory configurations diverge in capacity and type. The MI300A uses 128 GB of HBM3 with an 8192 bit bus and 5.32 TB/s of bandwidth. The B300 uses 288 GB of HBM3e, also on an 8192 bit bus, with 8.19 TB/s of bandwidth. The B300 delivers over 2.25 times the memory capacity and roughly 54% more bandwidth. Memory clock rates are 1300 MHz (5.2 Gbps effective) on the AMD part versus 2000 MHz (8 Gbps effective) on the NVIDIA part.

Compute resources differ in structure. The MI300A has 14,592 shading units, 912 texture mapping units, and no ROPs, with a texture rate of 1,915.2 GTexel/s and FP32 performance of 61.29 TFLOPS. The B300 has 18,944 shading units, 592 TMUs, 24 ROPs, and 592 tensor cores, with a texture rate of 1,202.9 GTexel/s and FP32 performance of 76.99 TFLOPS. The B300 also records FP16 performance of 76.99 TFLOPS at a 1:1 ratio with FP32, while the MI300A lists no FP16 figure. The B300 has a pixel rate of 48.77 GPixel/s, while the MI300A is rated at 0 MPixel/s.

Power and interface specifications place these cards in different server classes. The MI300A has a TDP of 750 W with a suggested PSU of 1150 W, uses an OAM Module slot, and has no power connectors listed. The B300 has a TDP of 1100 W with a suggested PSU of 1500 W, uses an SXM Module slot, and lists no power connector details. The bus interfaces differ: PCIe 5.0 x16 for the AMD part and PCIe 6.0 x16 for the NVIDIA part. Neither card has display outputs, and both list no API support for DirectX, OpenGL, or Vulkan, confirming their compute-only purpose.

Head-to-Head Benchmarks

The database contains no head-to-head benchmark entries between the MI300A and the B300 SXM6 AC. The only performance measurement available is the B300's Geekbench OpenCL score of 369,831, which anchors its position at the 100th percentile of all GPUs. The MI300A has an average benchmark score of zero and no entries in its benchmark array.

The B300's score becomes meaningful when compared to its nearest rivals, all of which have recorded average scores. The NVIDIA B200 scores 345,482, putting the B300 ahead by 7%. The NVIDIA H200 NVL scores 334,891, a 10.4% gap. The AMD Instinct MI300X scores 317,994, a 16.3% gap. The NVIDIA L40S scores 295,763, a 25% gap. Each of these deltas confirms that the B300 delivers a measurable performance increase over every recorded competitor.

The MI300A cannot be placed in this ranking. Its lack of benchmark data means no delta can be computed against the B300 or any other accelerator. The database records its percentile as 50, which reflects the absence of measurements rather than a demonstrated mid-pack performance level.

FAQ

Q: Which accelerator has the higher recorded benchmark score?

A: The NVIDIA B300 SXM6 AC has the only recorded score, a Geekbench OpenCL result of 369,831, placing it at the 100th percentile. The AMD Instinct MI300A has no benchmark scores in the database.

Q: How does the B300 compare to its nearest rivals?

A: The B300 leads the NVIDIA B200 by 7%, the NVIDIA H200 NVL by 10.4%, the AMD Instinct MI300X by 16.3%, and the NVIDIA L40S by 25% based on average scores of 345,482, 334,891, 317,994, and 295,763 respectively.

Q: Which card has more memory capacity?

A: The NVIDIA B300 SXM6 AC has 288 GB of HBM3e memory, while the AMD Instinct MI300A has 128 GB of HBM3 memory.

Q: What are the power requirements for each card?

A: The AMD Instinct MI300A has a TDP of 750 W and a suggested PSU of 1150 W. The NVIDIA B300 SXM6 AC has a TDP of 1100 W and a suggested PSU of 1500 W.

Q: Which architecture uses a higher base clock?

A: The NVIDIA B300 SXM6 AC has a base clock of 1665 MHz, while the AMD Instinct MI300A has a base clock of 1000 MHz. The AMD part has a higher boost clock at 2100 MHz versus 2032 MHz for the NVIDIA part.

Q: Do either of these cards support graphics APIs?

A: Neither card supports DirectX, OpenGL, or Vulkan, and both have no display outputs, indicating they are compute-only accelerators.

Where Each One Wins

The NVIDIA B300 SXM6 AC wins in every category where the database has measurable evidence. Its Geekbench OpenCL score of 369,831 is the definitive performance data point, and the 7% to 25% margins over its nearest rivals confirm its position at the top of the recorded rankings. It also leads in raw specification areas that support compute throughput: higher FP32 performance at 76.99 TFLOPS versus 61.29 TFLOPS, FP16 capability at 76.99 TFLOPS where the MI300A lists none, more shading units at 18,944 versus 14,592, tensor cores present at 592, larger memory capacity at 288 GB versus 128 GB, faster memory bandwidth at 8.19 TB/s versus 5.32 TB/s, a higher base clock at 1665 MHz versus 1000 MHz, a newer PCIe 6.0 x16 interface versus PCIe 5.0 x16, and a larger transistor budget at 208,000 million versus 153,000 million.

The AMD Instinct MI300A wins in a narrower set of specification comparisons. It has a higher transistor density at 150.4 million per mm² versus 127.8 million per mm², a higher boost clock at 2100 MHz versus 2032 MHz, more texture mapping units at 912 versus 592, a higher texture rate at 1,915.2 GTexel/s versus 1,202.9 GTexel/s, and a lower TDP at 750 W versus 1100 W. These advantages are real in the specification sheet, but the database contains no benchmark result to translate them into a performance win.

For workloads that depend on measured compute output, the B300 is the clear choice. For workloads that prioritize texture throughput, higher boost frequencies, or lower power draw, the MI300A's specifications offer theoretical advantages, but without recorded benchmarks, those advantages remain unverified.

Specification Differences

The two accelerators differ across nearly every recorded specification field.

Process and silicon: Both use TSMC 5 nm, but the B300 has 208,000 million transistors on a 1628 mm² die, while the MI300A has 153,000 million on 1017 mm². Transistor density favors the MI300A at 150.4M per mm² versus 127.8M per mm².

Clocks: The MI300A has a base clock of 1000 MHz and a boost of 2100 MHz. The B300 has a base of 1665 MHz and a boost of 2032 MHz. Memory clocks are 1300 MHz (5.2 Gbps effective) for the MI300A and 2000 MHz (8 Gbps effective) for the B300.

Memory: The MI300A has 128 GB of HBM3 with 5.32 TB/s bandwidth. The B300 has 288 GB of HBM3e with 8.19 TB/s bandwidth. Both use an 8192 bit bus.

Compute units: The MI300A has 14,592 shading units, 912 TMUs, and 0 ROPs. The B300 has 18,944 shading units, 592 TMUs, and 24 ROPs. The B300 includes 592 tensor cores; the MI300A lists none.

Performance rates: FP32 is 61.29 TFLOPS for the MI300A and 76.99 TFLOPS for the B300. FP16 is not listed for the MI300A and is 76.99 TFLOPS (1:1) for the B300. Texture rate is 1,915.2 GTexel/s for the MI300A and 1,202.9 GTexel/s for the B300. Pixel rate is 0 MPixel/s for the MI300A and 48.77 GPixel/s for the B300.

Power and cooling: TDP is 750 W for the MI300A and 1100 W for the B300. Suggested PSU is 1150 W versus 1500 W. The MI300A uses an OAM Module slot; the B300 uses an SXM Module slot. The MI300A lists no power connectors; the B300 also lists none.

Interface: The MI300A uses PCIe 5.0 x16. The B300 uses PCIe 6.0 x16.

Release timing: The MI300A was released on 2023-12-05. The B300 was released on 2025-09-10 and has an active production status. The MI300A's production status is not recorded. The B300 lists a predecessor of Server Hopper and a successor of Server Rubin; the MI300A lists a predecessor of Radeon Instinct and no successor. Neither card has a launch MSRP in the database.