AMD Instinct MI300X vs AMD Radeon Instinct MI300 Comparison

# Where Each One Wins

The AMD Instinct MI300X and the AMD Radeon Instinct MI300 share the same Aqua Vanjaram chip and CDNA 3.0 architecture, but the recorded data shows they are positioned for distinctly different workloads. The MI300X is the only one of the two with a benchmark score in the database, posting 317,994 in Geekbench OpenCL. That score places it at the 100th percentile of all GPUs tracked, meaning the database records no other accelerator with a higher percentile ranking. The Radeon Instinct MI300, by contrast, has no recorded benchmark scores and sits at the 50th percentile, which reflects an absence of measured data rather than a measured performance level.

The MI300X wins on compute throughput in every measured category because it carries more active silicon. It has 19,456 shading units against 14,080 on the MI300, a difference of 5,376 shading units. That advantage translates directly to 81.72 TFLOPS of FP32 performance versus 47.87 TFLOPS, a gap of 33.85 TFLOPS, or roughly 71% higher. Texture rate follows the same pattern: 2,553.6 GTexel/s on the MI300X versus 1,496.0 GTexel/s on the MI300, a 1,057.6 GTexel/s delta. The MI300X also boosts to 2100 MHz compared to 1700 MHz on the MI300, a 400 MHz difference in maximum clock speed.

The MI300 wins where memory capacity and bandwidth matter more than raw shader count. The database shows the MI300 delivering 6.55 TB/s of memory bandwidth against 5.32 TB/s on the MI300X, a 1.23 TB/s advantage. It also runs its HBM3 memory at 1600 MHz (6.4 Gbps effective) versus 1300 MHz (5.2 Gbps effective) on the MI300X. In FP16 compute, the MI300 reaches 383.0 TFLOPS using an 8:1 ratio, while the MI300X manages 81.72 TFLOPS at a 1:1 ratio. The MI300's FP16 number is 301.28 TFLOPS higher, though the ratio difference means the two parts are not directly comparable in that metric. The MI300 also draws 600 W against 750 W for the MI300X, a 150 W lower thermal envelope.

The use-case split is clear from the measured fields: the MI300X is the general-purpose FP32 throughput leader and the only one of the pair with a recorded performance score, while the MI300 is the memory-bandwidth and FP16-throughput specialist that also fits into a lower power budget.

FAQ

Q: Which accelerator has the higher recorded benchmark score?

A: The AMD Instinct MI300X has a Geekbench OpenCL score of 317,994, placing it at the 100th percentile of all GPUs in the database. The AMD Radeon Instinct MI300 has no recorded benchmark scores and sits at the 50th percentile.

Q: How do the two compare on FP32 compute performance?

A: The MI300X delivers 81.72 TFLOPS of FP32 performance, while the MI300 delivers 47.87 TFLOPS. The MI300X is therefore 33.85 TFLOPS higher, which is about 71% faster in this metric.

Q: Does the MI300 have any performance advantage over the MI300X?

A: Yes. The MI300 has 6.55 TB/s of memory bandwidth versus 5.32 TB/s on the MI300X, a 1.23 TB/s advantage. It also reaches 383.0 TFLOPS in FP16 at an 8:1 ratio, compared to 81.72 TFLOPS at a 1:1 ratio on the MI300X.

Q: What are the clock speed differences between the two cards?

A: Both have a 1000 MHz base clock. The MI300X boosts to 2100 MHz, while the MI300 boosts to 1700 MHz. The memory clocks also differ: the MI300X runs at 1300 MHz (5.2 Gbps effective), and the MI300 runs at 1600 MHz (6.4 Gbps effective).

Q: How do the memory configurations differ?

A: The MI300X has 192 GB of HBM3 memory on an 8192-bit bus. The MI300 has 128 GB of HBM3 memory, also on an 8192-bit bus. The MI300 has higher bandwidth per byte due to its faster memory clock.

Q: Do both cards use the same physical chip?

A: Yes. Both the MI300X and the MI300 use the Aqua Vanjaram chip built on TSMC's 5 nm process, with 153,000 million transistors on a 1017 mm² die and a transistor density of 150.4M per mm². The differences come from how the chip is configured, not the underlying silicon.

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark entries for these two accelerators, but the MI300X has a Geekbench OpenCL score of 317,994 while the MI300 has no score at all. That single measurement still allows meaningful comparison through the MI300X's nearest rival data. The NVIDIA H200 NVL scores 334,891, which is 5% higher than the MI300X. The NVIDIA B200 scores 345,482, 8% higher. The MI300X beats the NVIDIA L40S, which scores 295,763, by 7.5%, and it beats the NVIDIA RTX 6000 Ada Generation, which scores 287,237, by 10.7%. These deltas frame the MI300X's position: it sits in the upper tier of recorded accelerators, behind the H200 NVL and B200 but ahead of the L40S and RTX 6000 Ada Generation.

The MI300 has no comparable measurement, so its position comes from specification analysis. The MI300X's 81.72 TFLOPS FP32 figure exceeds the MI300's 47.87 TFLOPS by 33.85 TFLOPS. The texture rate gap is similarly lopsided: 2,553.6 GTexel/s versus 1,496.0 GTexel/s. Both parts report 0 MPixel/s pixel rate and 0 ROPs, so neither is designed for rasterization-style output.

The MI300's strongest counters are memory and FP16. Its 6.55 TB/s bandwidth is 23% higher than the MI300X's 5.32 TB/s. Its FP16 throughput of 383.0 TFLOPS at an 8:1 ratio is 301.28 TFLOPS above the MI300X's 81.72 TFLOPS at a 1:1 ratio. The MI300 also uses 150 W less power, 600 W versus 750 W, and requires a 1000 W suggested PSU against the MI300X's 1150 W.

The biggest single-spec win for the MI300X is FP32 compute, where it leads by 33.85 TFLOPS. The biggest single-spec win for the MI300 is FP16 throughput, where it leads by 301.28 TFLOPS under its 8:1 ratio. In memory bandwidth, the MI300 leads by 1.23 TB/s. In texture rate, the MI300X leads by 1,057.6 GTexel/s. Both cards share an 8192-bit memory bus, but the MI300's faster memory clock of 1600 MHz versus 1300 MHz is what produces its bandwidth advantage.

Specification Differences

The two cards differ across compute, memory, clocks, power, and physical configuration. The MI300X has 19,456 shading units, 1,216 TMUs, and 0 ROPs. The MI300 has 14,080 shading units, 880 TMUs, and 0 ROPs. That means the MI300X carries 5,376 more shading units and 336 more TMUs. FP32 output is 81.72 TFLOPS on the MI300X and 47.87 TFLOPS on the MI300. FP16 output is 81.72 TFLOPS at a 1:1 ratio on the MI300X and 383.0 TFLOPS at an 8:1 ratio on the MI300. Texture rate is 2,553.6 GTexel/s versus 1,496.0 GTexel/s. Pixel rate is 0 MPixel/s on both.

Memory differs in size and speed but not bus width. The MI300X has 192 GB of HBM3 on an 8192-bit bus with 5.32 TB/s bandwidth. The MI300 has 128 GB of HBM3 on an 8192-bit bus with 6.55 TB/s bandwidth. The MI300X memory clock is 1300 MHz (5.2 Gbps effective); the MI300 memory clock is 1600 MHz (6.4 Gbps effective).

Clocks differ only at the boost level. Base clock is 1000 MHz on both. Boost clock is 2100 MHz on the MI300X and 1700 MHz on the MI300. Power figures also differ: the MI300X is rated at 750 W with no power connectors and a suggested PSU of 1150 W, while the MI300 is rated at 600 W with 2x 8-pin power connectors and a suggested PSU of 1000 W.

Physical and interface details show some divergence. The MI300X is listed as an OAM Module with no display outputs. The MI300 has no slot width listed, uses a PCIe 5.0 x16 interface, has no display outputs, and measures 267 mm in length and 111 mm in height. Both use the PCIe 5.0 x16 bus interface. The MI300X has no listed dimensions. Release dates differ: the MI300 launched on 2023-01-03, and the MI300X launched on 2023-12-05.

Architecture Differences

Both accelerators are built on the Aqua Vanjaram chip using AMD's CDNA 3.0 architecture, fabricated by TSMC on a 5 nm process. The transistor count is identical at 153,000 million, the die size is identical at 1017 mm², and the transistor density is identical at 150.4M per mm². The architecture is the same; the differentiation comes from how the chip is partitioned and clocked.

The MI300X uses a higher boost clock of 2100 MHz versus 1700 MHz on the MI300, which contributes to its 33.85 TFLOPS lead in FP32. The MI300 compensates with a faster memory clock of 1600 MHz versus 1300 MHz, which drives its 6.55 TB/s bandwidth figure. The MI300's FP16 ratio of 8:1 versus the MI300X's 1:1 indicates a different execution path for reduced-precision workloads, though both share the same CDNA 3.0 generation.

The MI300X is configured with 192 GB of HBM3, while the MI300 has 128 GB, a 64 GB difference. Both use an 8192-bit memory bus, so the MI300 achieves higher bandwidth with less memory by running its HBM3 stacks faster. The power delivery differs as well: the MI300X is an OAM Module with no power connectors and a 750 W TDP, while the MI300 uses 2x 8-pin connectors and a 600 W TDP.

Neither part has RT cores or tensor cores listed, and neither has a DirectX, OpenGL, or Vulkan API rating. The MI300X lists those APIs as N/A; the MI300 has null entries. Both have no display outputs and no pixel rate. The MI300X belongs to the Instinct (MIx) generation, and the MI300 belongs to the Radeon Instinct (MIx) generation, making the MI300X the later release by roughly 11 months. The MI300's predecessor is listed as FirePro Data Center, while the MI300X's predecessor is Radeon Instinct.