AMD Instinct MI300 vs AMD Instinct MI325X Comparison

Head-to-Head Benchmarks

The recorded database contains no direct benchmark scores for either the AMD Instinct MI300 or the AMD Instinct MI325X. Both parts show an average benchmark score of 0 and occupy the 50th percentile against all GPUs in the database. This means there are no measured performance deltas to cite, no win counts to assign, and no nearest rival comparisons available for either accelerator.

What the data does provide is a clear set of compute specifications that can be read as theoretical peak throughput values. The MI325X delivers 81.72 TFLOPS for both FP32 and FP16 (1:1) operations. The MI300 delivers 47.87 TFLOPS for the same precision formats. The difference works out to roughly 70.7% higher peak compute on the MI325X, which is the single largest compute gap between the two parts. Texture rate follows the same pattern: the MI325X reaches 2,553.6 GTexel/s, while the MI300 reaches 1,496.0 GTexel/s, a gap of about 70.7% as well, driven by the MI325X having 1,216 TMUs versus 880 TMUs on the MI300.

Memory bandwidth shows a smaller but still substantial advantage for the newer part. The MI325X records 6.14 TB/s of bandwidth from its HBM3e stack, while the MI300 records 5.32 TB/s from HBM3. That is roughly 15.4% more bandwidth on the MI325X. Both parts share the same 8192-bit memory bus width, so the bandwidth gain comes entirely from the faster memory clock: the MI325X runs its memory at 1500 MHz (6 Gbps effective), while the MI300 runs at 1300 MHz (5.2 Gbps effective).

Clock speeds also favor the MI325X. The boost clock is 2100 MHz on the MI325X versus 1700 MHz on the MI300, a 23.5% higher boost figure. Base clocks are identical at 1000 MHz. The shading unit count scales similarly: 19,456 shading units on the MI325X versus 14,080 on the MI300, a 38.2% increase. The MI325X also doubles memory capacity to 256 GB from 128 GB on the MI300.

Pixel rate is 0 MPixel/s for both parts, and neither has any display outputs, which is consistent with the absence of render output units (ROPs) in the recorded data. Both chips use PCIe 5.0 x16 as the bus interface, and both have no DirectX, OpenGL, or Vulkan API support listed.

FAQ

Q: Which accelerator has higher peak FP32 compute in the database?

A: The AMD Instinct MI325X records 81.72 TFLOPS for FP32, while the AMD Instinct MI300 records 47.87 TFLOPS. The MI325X is approximately 70.7% higher.

Q: What memory capacity and type does each part use?

A: The MI300 uses 128 GB of HBM3, while the MI325X uses 256 GB of HBM3e. Both have an 8192-bit memory bus.

Q: Are there any measured benchmark scores or rival comparisons for these two accelerators?

A: No. Both parts have an average benchmark score of 0, a 50th percentile rating against all GPUs, and no nearest rival entries in the database.

Q: How do the memory bandwidth figures compare?

A: The MI300 records 5.32 TB/s, and the MI325X records 6.14 TB/s, which is about 15.4% higher.

Q: Do the two accelerators share the same silicon?

A: Yes. Both use the Aqua Vanjaram chip, CDNA 3.0 architecture, a 5 nm TSMC process, 153,000 million transistors, and a 1017 mm² die size.

Q: What are the power requirements listed for each?

A: The MI300 has a TDP of 600 W and a suggested PSU of 1000 W, with 2x 8-pin power connectors. The MI325X has a TDP of 1000 W and a suggested PSU of 1400 W, with no power connectors listed because it is an OAM module.

Architecture Differences

The two accelerators share the same fundamental silicon. Both are built on the Aqua Vanjaram chip, use CDNA 3.0 architecture, and are fabricated by TSMC on a 5 nm process. The transistor count is identical at 153,000 million, and the die size is identical at 1017 mm², giving both a transistor density of 150.4M per mm². The generation field for both is listed as "Instinct (MIx)", and both share the same predecessor, Radeon Instinct.

The architectural differences appear in the execution resources and memory subsystem. The MI325X scales up the compute units substantially: 19,456 shading units versus 14,080 on the MI300, and 1,216 TMUs versus 880. Neither part has ROPs, and both have a pixel rate of 0 MPixel/s. The MI325X also raises the boost clock from 1700 MHz to 2100 MHz while keeping the base clock at 1000 MHz.

Memory architecture diverges in type and speed. The MI300 uses HBM3 with a 1300 MHz memory clock (5.2 Gbps effective), while the MI325X uses HBM3e with a 1500 MHz memory clock (6 Gbps effective). The bus width stays at 8192 bits for both, but the higher memory clock and newer memory type push the MI325X to 6.14 TB/s versus 5.32 TB/s. Capacity doubles from 128 GB to 256 GB.

Both parts are compute-focused accelerators with no display outputs and no graphics API support. Both use PCIe 5.0 x16 for host connectivity. The MI325X is classified as an OAM module, while the MI300 lists 2x 8-pin power connectors and a 267 mm length, 111 mm height physical footprint. The MI325X has no dimensions recorded in the database.

Specification Differences

The differences in recorded specifications are as follows:

• Boost clock: MI300 at 1700 MHz, MI325X at 2100 MHz (base clock identical at 1000 MHz).
• Memory clock: MI300 at 1300 MHz (5.2 Gbps effective), MI325X at 1500 MHz (6 Gbps effective).
• Memory size: MI300 at 128 GB, MI325X at 256 GB.
• Memory type: MI300 uses HBM3, MI325X uses HBM3e.
• Memory bandwidth: MI300 at 5.32 TB/s, MI325X at 6.14 TB/s.
• Shading units: MI300 at 14,080, MI325X at 19,456.
• TMUs: MI300 at 880, MI325X at 1,216.
• Texture rate: MI300 at 1,496.0 GTexel/s, MI325X at 2,553.6 GTexel/s.
• FP32 compute: MI300 at 47.87 TFLOPS, MI325X at 81.72 TFLOPS.
• FP16 compute: MI300 at 47.87 TFLOPS (1:1), MI325X at 81.72 TFLOPS (1:1).
• TDP: MI300 at 600 W, MI325X at 1000 W.
• Suggested PSU: MI300 at 1000 W, MI325X at 1400 W.
• Power connectors: MI300 lists 2x 8-pin, MI325X lists none.
• Slot width: MI300 has no listed value, MI325X is listed as OAM Module.
• Dimensions: MI300 is 267 mm long and 111 mm high, MI325X has no dimensions listed.
• Release date: MI300 released on 2023-01-03, MI325X on 2024-10-09.

Fields that are identical: manufacturer (AMD), chip (Aqua Vanjaram), architecture (CDNA 3.0), generation (Instinct (MIx)), process node (5 nm), foundry (TSMC), transistors (153,000 million), die size (1017 mm²), transistor density (150.4M / mm²), ROPs (0), pixel rate (0 MPixel/s), bus interface (PCIe 5.0 x16), display outputs (no outputs), graphics APIs (N/A for all), and predecessor (Radeon Instinct). Neither part has a launch MSRP recorded.

The Verdict

The data points to a clear generational split. The MI325X holds the advantage in every compute and memory metric that is recorded: higher boost clock, higher memory clock, double the memory capacity, newer memory type, higher bandwidth, more shading units, more TMUs, higher texture rate, and roughly 70.7% higher FP32 and FP16 peak compute. It also carries a higher power envelope, with TDP rising from 600 W to 1000 W and suggested PSU rising from 1000 W to 1400 W, plus a form factor change to an OAM module with no discrete power connectors listed.

The MI300 remains the lower-power, air-cooled-capable option in the pair, with a 267 mm board length and 111 mm height, 2x 8-pin power connectors, and a 600 W TDP. Its 128 GB of HBM3 and 5.32 TB/s of bandwidth are still substantial figures, but they sit below the MI325X on every axis that the database records.

There are no measured benchmark scores or rival comparisons for either part, so the verdict rests entirely on specification data. The MI325X is the higher-performance accelerator by the recorded metrics, and the MI300 is the lower-power, lower-bandwidth, lower-compute option. The choice between them depends on whether the workload requires the MI325X's doubled memory capacity, higher bandwidth, and higher peak throughput, or whether the MI300's lower power draw and conventional 8-pin power connectivity fit the deployment constraints better. The data does not indicate any scenario where the MI300 outperforms the MI325X.