AMD Instinct MI300A vs NVIDIA B300 Comparison

Where Each One Wins

The recorded data for these two accelerator modules shows no direct head-to-head benchmark results, so the comparison rests entirely on their architectural specifications and derived capabilities. The AMD Instinct MI300A and NVIDIA B300 serve distinct roles in high-performance computing, and the specification sheets reveal where each one holds a clear advantage.

The AMD Instinct MI300A delivers a texture rate of 1,915.2 GTexel/s, which is roughly 59% higher than the NVIDIA B300's 1,202.9 GTexel/s. This positions the MI300A as the stronger choice for workloads that depend heavily on texture sampling and fill-rate-bound operations, such as certain visualization pipelines or scientific rendering tasks. Its memory bus width of 8192 bit also gives it a substantial lead in memory parallelism, doubling the B300's 4096 bit interface.

The NVIDIA B300, however, counters with a higher FP32 throughput of 76.99 TFLOPS versus the MI300A's 61.29 TFLOPS, a 25.6% advantage in single-precision floating-point compute. This makes the B300 more suited to general compute workloads that rely on FP32 arithmetic, including many AI training and inference tasks that operate in that precision. Additionally, the B300's FP16 figure of 1,231.8 TFLOPS (16:1) is a dramatic leap over the MI300A, which lists no FP16 specification at all, indicating a clear design focus on mixed-precision machine learning workloads.

In memory capacity, the NVIDIA B300 offers 144 GB of HBM3e, exceeding the MI300A's 128 GB of HBM3 by 16 GB. This extra capacity matters for large models or datasets that must reside in on-package memory to avoid PCIe transfers. However, the MI300A's memory bandwidth of 5.32 TB/s outstrips the B300's 4.10 TB/s by about 29.8%, meaning the AMD part can feed its compute units faster when memory access patterns are bandwidth-bound.

Clock speeds also differentiate the two. The B300 has a higher base clock of 1665 MHz against the MI300A's 1000 MHz, and a boost clock of 2032 MHz versus 2100 MHz for the AMD part. The AMD accelerator actually boosts higher, reaching 2100 MHz, which suggests it can sustain aggressive frequency in burst scenarios despite its lower base. The B300's base clock advantage points to a more consistent performance floor.

Architecture Differences

The two accelerators come from fundamentally different design lineages. The AMD Instinct MI300A uses the Aqua Vanjaram chip built on CDNA 3.0 architecture, while the NVIDIA B300 uses the GB110 chip based on Blackwell Ultra architecture. Both are fabricated on a 5 nm process at TSMC, but the transistor counts diverge sharply. The MI300A packs 153,000 million transistors on a 1017 mm² die, yielding a density of 150.4 million transistors per square millimeter. The B300 contains 104,000 million transistors, and the database does not record a die size or density for it.

Shader core counts also differ. The MI300A carries 14,592 shading units and 912 texture mapping units, with no ROPs listed. The B300 has 18,944 shading units, 592 TMUs, and 24 ROPs. The B300's higher shading unit count supports its FP32 advantage, while the MI300A's TMU count drives its texture throughput lead. The B300 also includes 592 tensor cores, a feature class absent from the MI300A's specification sheet.

Memory technology differs as well. The MI300A uses HBM3 with a 8192 bit bus, while the B300 uses HBM3e with a 4096 bit bus. The HBM3e standard offers higher per-pin data rates, as reflected in the B300's 8 Gbps effective memory clock against the MI300A's 5.2 Gbps effective. Yet the MI300A's wider bus compensates, resulting in its higher aggregate bandwidth of 5.32 TB/s versus 4.10 TB/s.

Power and packaging also separate the two. The MI300A has a TDP of 750 W and uses an OAM Module slot width, with no power connectors listed and a suggested PSU of 1150 W. The B300 draws a TDP of 1400 W, uses an SXM Module slot, and requires a suggested 1800 W PSU. Both use PCIe 5.0 x16 interfaces and have no display outputs. The release dates show the MI300A arriving on 2023-12-05, while the B300 launched on 2025-09-10, giving the NVIDIA part nearly two years of additional design time.

FAQ

Q: Which accelerator has higher memory bandwidth?

A: The AMD Instinct MI300A leads with 5.32 TB/s of memory bandwidth, compared to the NVIDIA B300's 4.10 TB/s. This advantage stems from the MI300A's 8192 bit memory bus versus the B300's 4096 bit bus.

Q: What is the FP32 performance difference between the two?

A: The NVIDIA B300 delivers 76.99 TFLOPS of FP32 throughput, while the AMD Instinct MI300A provides 61.29 TFLOPS. The B300 is approximately 25.6% faster in single-precision compute.

Q: How much memory does each accelerator offer?

A: The NVIDIA B300 has 144 GB of HBM3e memory, while the AMD Instinct MI300A has 128 GB of HBM3 memory. The B300 offers 16 GB more capacity.

Q: Which part has more shading units?

A: The NVIDIA B300 has 18,944 shading units, compared to the AMD Instinct MI300A's 14,592 shading units. The B300 also has 592 tensor cores, a feature the MI300A does not list.

Q: What are the power requirements for each module?

A: The AMD Instinct MI300A has a TDP of 750 W and a suggested PSU of 1150 W. The NVIDIA B300 has a TDP of 1400 W and a suggested PSU of 1800 W. The B300 draws substantially more power.

Q: When did each accelerator launch?

A: The AMD Instinct MI300A launched on 2023-12-05, and the NVIDIA B300 launched on 2025-09-10. The B300 is the newer product by nearly two years.

Specification Differences

The two accelerators differ across nearly every major specification category. The AMD Instinct MI300A uses the Aqua Vanjaram chip with CDNA 3.0 architecture, while the NVIDIA B300 uses the GB110 chip with Blackwell Ultra architecture. Transistor counts differ at 153,000 million for the MI300A and 104,000 million for the B300. The MI300A records a die size of 1017 mm² and a density of 150.4 million transistors per square millimeter; the B300 records neither.

Clock specifications diverge: the MI300A has a base clock of 1000 MHz and a boost of 2100 MHz, while the B300 has a base of 1665 MHz and a boost of 2032 MHz. Memory clocks also differ, with the MI300A at 1300 MHz (5.2 Gbps effective) and the B300 at 2000 MHz (8 Gbps effective). The memory type differs between HBM3 (MI300A) and HBM3e (B300), as do the capacities at 128 GB versus 144 GB, bus widths at 8192 bit versus 4096 bit, and bandwidths at 5.32 TB/s versus 4.10 TB/s.

Shading units number 14,592 for the MI300A and 18,944 for the B300. Texture mapping units are 912 for the AMD part and 592 for the NVIDIA part. The MI300A lists 0 ROPs and 0 pixel rate, while the B300 has 24 ROPs and a pixel rate of 48.77 GPixel/s. Texture rates are 1,915.2 GTexel/s for the MI300A and 1,202.9 GTexel/s for the B300. FP32 performance sits at 61.29 TFLOPS for the MI300A and 76.99 TFLOPS for the B300, with the B300 also listing FP16 at 1,231.8 TFLOPS (16:1) and 592 tensor cores.

Power figures are 750 W TDP for the MI300A versus 1400 W for the B300. Slot widths differ between OAM Module and SXM Module. The MI300A lists no power connectors, while the B300 leaves that field blank. Suggested PSU values are 1150 W for the AMD part and 1800 W for the NVIDIA part. The MI300A has a production status of null, while the B300 is marked Active. Release dates are 2023-12-05 for the MI300A and 2025-09-10 for the B300. The MI300A's predecessor is Radeon Instinct, and the B300's predecessor is Server Hopper, with its successor listed as Server Rubin.

Head-to-Head Benchmarks

The database contains no recorded head-to-head benchmark results between the AMD Instinct MI300A and NVIDIA B300, and both parts show an average benchmark score of 0 with no nearest rivals listed. The comparison therefore draws entirely on the specification sheets, which nonetheless reveal decisive advantages in each direction.

The largest win for the AMD Instinct MI300A comes in memory bandwidth. At 5.32 TB/s, it exceeds the NVIDIA B300's 4.10 TB/s by 1.22 TB/s, a 29.8% margin. This is a substantial lead for any memory-bound workload, including large sparse matrix operations or data movement heavy scientific codes. The MI300A also leads decisively in texture rate at 1,915.2 GTexel/s versus 1,202.9 GTexel/s, a 59.2% advantage that reflects its 912 TMUs against the B300's 592 TMUs. The memory bus width of 8192 bit versus 4096 bit reinforces this pattern, giving the AMD part a structural advantage in parallel memory access.

The NVIDIA B300's clearest victories lie in compute throughput and capacity. Its FP32 output of 76.99 TFLOPS beats the MI300A's 61.29 TFLOPS by 15.70 TFLOPS, a 25.6% edge. The B300's FP16 specification of 1,231.8 TFLOPS (16:1) is transformative in comparison, since the MI300A lists no FP16 figure at all, indicating the NVIDIA part is engineered for tensor-heavy machine learning workloads. The B300 also holds a 16 GB memory capacity advantage at 144 GB versus 128 GB, which can be the deciding factor for models that approach the memory ceiling.

Shading unit counts favor the B300 at 18,944 versus 14,592, a 29.8% higher count that aligns with its FP32 lead. The B300's base clock of 1665 MHz versus 1000 MHz gives it a 66.5% higher frequency floor, though the MI300A's boost clock of 2100 MHz slightly exceeds the B300's 2032 MHz. Pixel throughput is exclusive to the B300 at 48.77 GPixel/s, since the MI300A lists a pixel rate of 0 MPixel/s.

Power consumption data shows the B300 at 1400 W TDP, nearly double the MI300A's 750 W, with suggested PSU requirements of 1800 W versus 1150 W. The tradeoff is clear: the B300 consumes more power to achieve higher FP32 and FP16 throughput, while the MI300A delivers superior bandwidth and texture rates at a lower power envelope. The B300's production status of Active, against a null status for the MI300A, suggests the NVIDIA part is currently in production, while the AMD part's status remains unrecorded. Both modules share the PCIe 5.0 x16 interface and have no display outputs, reinforcing their roles as compute-only accelerators.