AMD Instinct MI300A vs AMD Instinct MI308X Comparison

Head-to-Head Benchmarks

The recorded database contains no benchmark scores for either the AMD Instinct MI300A or the AMD Instinct MI308X. Both parts show an average benchmark score of zero, and the head-to-head benchmark list is empty. Consequently, there are no measured wins for either accelerator in direct comparison. The percentile versus all GPUs is identical at 50 for both, placing them at the exact midpoint of the database distribution, although this is a positional rank rather than a performance figure.

Without empirical scores, the comparison must rely on the specification-derived compute metrics recorded in the database. The MI308X delivers 81.72 TFLOPS of FP32 throughput, while the MI300A delivers 61.29 TFLOPS. The recorded data therefore indicates the MI308X holds a 33.3% advantage in raw FP32 compute. Texture rate follows the same pattern: the MI308X reaches 2,553.6 GTexel/s versus 1,915.2 GTexel/s for the MI300A, a difference of 33.3% as well, driven by the larger texture unit count of 1,216 versus 912. Both parts report a pixel rate of 0 MPixel/s, which reflects their server-oriented design with no conventional raster output pipeline.

Memory capacity is the other major differentiator. The MI308X carries 192 GB of HBM3, while the MI300A carries 128 GB. That is a 50% larger memory pool for the MI308X. Notably, memory bandwidth is identical at 5.32 TB/s for both, and the bus width is the same 8,192 bits, so the additional capacity does not translate to additional bandwidth. The MI308X uses the same memory clock of 1300 MHz (5.2 Gbps effective) as the MI300A.

FP16 data reveals an interesting asymmetry. The MI308X lists FP16 at 81.72 TFLOPS with a 1:1 ratio to FP32, meaning it does not gain a throughput advantage in reduced precision. The MI300A has no FP16 figure recorded in the database. The absence of that field makes a direct FP16 comparison impossible, but the MI308X is the only one of the two with confirmed FP16 capability in the record.

The wins tally in the database shows zero wins for each side, which is consistent with the empty benchmark array. The specification comparison, however, gives the MI308X clear leads in shading units (19,456 versus 14,592), texture mapping units (1,216 versus 912), FP32 throughput, texture rate, and memory capacity. The MI300A has no specification advantage in any recorded field; the two are equal in clock speeds, memory bandwidth, memory type, bus width, transistor count, die size, process node, TDP, and power delivery requirements.

FAQ

Q: Which accelerator has higher FP32 compute performance?

A: The AMD Instinct MI308X records 81.72 TFLOPS of FP32, which is 33.3% higher than the 61.29 TFLOPS of the AMD Instinct MI300A.

Q: Do the two accelerators have the same memory bandwidth?

A: Yes. Both record 5.32 TB/s of bandwidth over an 8,192-bit bus using HBM3 memory at 1300 MHz (5.2 Gbps effective).

Q: How much more memory does the MI308X have?

A: The MI308X records 192 GB, while the MI300A records 128 GB. That is a 50% larger capacity, or 64 GB more.

Q: Are the clock speeds different between the two?

A: No. Both list a base clock of 1000 MHz and a boost clock of 2100 MHz. The memory clock is also identical at 1300 MHz.

Q: What is the texture rate difference?

A: The MI308X reaches 2,553.6 GTexel/s, while the MI300A reaches 1,915.2 GTexel/s. The MI308X is 33.3% faster in this metric.

Q: Do both cards use the same physical design?

A: The database shows both use an OAM Module slot width, have no power connectors, no display outputs, and require a suggested PSU of 1150 W. The chip, Aqua Vanjaram, is the same for both.

Architecture Differences

Both accelerators are built on the CDNA 3.0 architecture and share the same physical chip, codenamed Aqua Vanjaram. The process node is 5 nm at TSMC, and the transistor count is identical at 153,000 million. Die size is also the same at 1,017 mm², yielding a transistor density of 150.4 million transistors per mm² for each. The architecture generation is recorded as Instinct (MIx) for both, with a predecessor of Radeon Instinct and a release date of December 5, 2023.

The architectural distinction in the database is one of configuration, not design. Both parts expose no ray tracing cores and no tensor cores as separate fields; the CDNA 3.0 compute pipeline is expressed through shading units, texture units, and FP32 throughput. The MI308X configures 19,456 shading units and 1,216 texture mapping units, while the MI300A configures 14,592 shading units and 912 texture mapping units. This is a 33.3% increase in both unit counts for the MI308X, which explains the identical 33.3% increase in FP32 TFLOPS and texture rate.

The FP16 field is a notable architectural difference. The MI308X records FP16 at 81.72 TFLOPS with a 1:1 ratio, meaning the hardware does not double FP16 throughput relative to FP32. The MI300A has no FP16 entry at all in the database. The 1:1 ratio on the MI308X suggests the CDNA 3.0 implementation on this chip treats FP16 and FP32 with equal rate, rather than using a packed or dual-rate scheme. The MI300A record does not confirm whether FP16 is unsupported or simply unmeasured, but the database only verifies FP16 for the MI308X.

The memory subsystem architecture is largely shared. Both use HBM3, both use an 8,192-bit bus, and both achieve 5.32 TB/s. The difference is capacity: 192 GB on the MI308X versus 128 GB on the MI300A. Since the bus width and bandwidth are unchanged, the capacity increase on the MI308X comes from more memory stacks or higher-density stacks rather than a wider interface.

The compute architecture is identical in terms of clock behavior. Both list a 1000 MHz base and 2100 MHz boost, so the architectural difference is purely in the number of active compute units and the associated memory capacity. The power envelope is the same at 750 W TDP, with a suggested PSU of 1150 W, meaning the MI308X achieves its higher throughput within the same power budget. The pixel rate is 0 MPixel/s for both, consistent with a design that has no ROPs and no display output path.

Specification Differences

The two accelerators differ in exactly five recorded specification fields. Shading units are 19,456 on the MI308X versus 14,592 on the MI300A. Texture mapping units are 1,216 versus 912. FP32 throughput is 81.72 TFLOPS versus 61.29 TFLOPS. Texture rate is 2,553.6 GTexel/s versus 1,915.2 GTexel/s. Memory capacity is 192 GB versus 128 GB.

The MI308X alone records an FP16 value of 81.72 TFLOPS (1:1); the MI300A has no FP16 entry. All other fields are identical: base clock 1000 MHz, boost clock 2100 MHz, memory clock 1300 MHz (5.2 Gbps effective), memory type HBM3, memory bus width 8,192 bit, memory bandwidth 5.32 TB/s, pixel rate 0 MPixel/s, TDP 750 W, slot width OAM Module, power connectors None, suggested PSU 1150 W, bus interface PCIe 5.0 x16, display outputs No outputs, APIs N/A for DirectX, OpenGL, and Vulkan, chip Aqua Vanjaram, architecture CDNA 3.0, process node 5 nm, foundry TSMC, transistors 153,000 million, die size 1,017 mm², transistor density 150.4M / mm², generation Instinct (MIx), manufacturer AMD, release date December 5, 2023, predecessor Radeon Instinct, and production status not recorded.

The percentage differences are uniform across the compute metrics: the MI308X is 33.3% ahead in shading units, texture mapping units, FP32 TFLOPS, and texture rate. The memory capacity difference is larger at 50%, but it is confined to capacity alone; bandwidth does not scale. Neither part has a launch MSRP recorded, so no pricing comparison is available from the database.

The Verdict

The database record shows a clear hierarchy between these two accelerators. The AMD Instinct MI308X holds the specification advantage in every field where the two differ. Its 81.72 TFLOPS FP32 throughput is 33.3% higher than the MI300A's 61.29 TFLOPS, and its 192 GB memory capacity is 50% larger. The identical 1000 MHz base and 2100 MHz boost clocks, the same 5.32 TB/s bandwidth, and the same 750 W TDP mean the MI308X delivers its additional compute and capacity without any increase in power draw or memory speed.

The MI300A, by contrast, has no recorded advantage over the MI308X. It matches the MI308X in clocks, bandwidth, bus width, memory type, process node, die size, and power requirements, but it trails in shading units, texture units, FP32 throughput, texture rate, and memory capacity. For workloads that are bound by FP32 compute, the MI308X is the stronger part by 33.3%. For workloads that require large in-memory datasets, the MI308X provides 64 GB more capacity, a 50% increase, which can be decisive for models or data structures that approach the 128 GB limit of the MI300A.

The absence of benchmark scores in the database means the verdict rests on specification-derived metrics rather than measured application performance. The equal 50th percentile ranking for both parts reflects a lack of benchmark data, not equivalent performance. The recorded FP16 ratio of 1:1 on the MI308X indicates that mixed-precision workloads will not see a throughput bonus over FP32, so the MI308X advantage carries over to FP16 at the same 33.3% margin if the MI300A's FP16 capability were confirmed. The MI300A remains a functional accelerator with the same bandwidth, clocks, and power envelope, but the MI308X is the higher-configured variant of the same Aqua Vanjaram chip on every measurable specification in the database.