AMD Instinct MI300 vs NVIDIA Rubin GPU Comparison

Head-to-Head Benchmarks

The database records no head-to-head benchmark results for this pairing, and neither GPU has an average benchmark score or a wins tally. The AMD Instinct MI300 and NVIDIA Rubin GPU both sit at the 50th percentile versus all GPUs in the database, which indicates that the database has no measured performance data for either part at this time. Consequently, any performance comparison must rely on the architectural specifications and theoretical throughput figures recorded in the database, not on actual test runs.

The most significant numerical gap between the two lies in raw compute throughput. The NVIDIA Rubin GPU delivers 130.0 TFLOPS of FP32 performance, compared to 47.87 TFLOPS for the AMD Instinct MI300. That puts the Rubin at roughly 2.7 times the FP32 throughput of the MI300. In FP16, the divergence widens further: the Rubin achieves 260.0 TFLOPS (2:1 ratio), while the MI300 records 47.87 TFLOPS (1:1 ratio). The Rubin's FP16 output is over five times higher than the MI300's FP16 figure.

Texture and pixel rates follow a similar pattern, though the gap is narrower in texturing. The Rubin posts a texture rate of 2,031.2 GTexel/s against 1,496.0 GTexel/s for the MI300, a 35.8% advantage. Pixel throughput is a different story entirely. The MI300 has zero ROPs and records 0 MPixel/s, while the Rubin has 24 ROPs and delivers 54.41 GPixel/s. This makes the Rubin the only one of the two with any measurable pixel output capability.

Memory bandwidth shows the largest proportional difference. The Rubin's HBM4 memory subsystem provides 22.1 TB/s of bandwidth across a 16384-bit bus, while the MI300's HBM3 setup offers 5.32 TB/s across an 8192-bit bus. The Rubin's bandwidth is 4.15 times higher. Memory capacity also favors the Rubin: 288 GB versus 128 GB, a 2.25 times advantage.

Clock behavior differs markedly between the two. The MI300 has a base clock of 1000 MHz and a boost clock of 1700 MHz. The Rubin has a lower base of 700 MHz but a higher boost of 2267 MHz. The effective memory clock on the Rubin is 10.8 Gbps, double the 5.2 Gbps effective rate on the MI300. The Rubin's boost clock is 33.4% higher than the MI300's, which partially explains its throughput advantage despite a lower base clock.

Architecture Differences

The two GPUs come from different architectural generations and process nodes. The AMD Instinct MI300 uses the CDNA 3.0 architecture on a 5 nm TSMC process, featuring the Aqua Vanjaram chip. The NVIDIA Rubin GPU uses the Rubin architecture on a 3 nm TSMC process, featuring the GR100 chip. The Rubin's smaller process node allows for a substantially larger transistor count: 336,000 million transistors compared to 153,000 million on the MI300. Die size also differs, with the Rubin at 1456 mm² and the MI300 at 1017 mm². Transistor density favors the Rubin at 230.8M per mm² versus 150.4M per mm² for the MI300.

Shader and texture hardware differ significantly. The Rubin has 28,672 shading units and 896 TMUs, while the MI300 has 14,080 shading units and 880 TMUs. The Rubin more than doubles the shading units (2.04 times) but only edges out the MI300 in TMUs by 1.8%. The MI300 has zero ROPs, while the Rubin has 24. The Rubin also includes 896 tensor cores; the MI300 has no tensor core count recorded in the database.

Memory architecture is a major divergence point. The MI300 uses HBM3 memory with a 128 GB capacity, an 8192-bit bus, and 5.32 TB/s bandwidth. The Rubin uses HBM4 with 288 GB capacity, a 16384-bit bus (exactly double the width), and 22.1 TB/s bandwidth. The Rubin's memory clock runs at 2695 MHz with a 10.8 Gbps effective rate, versus 1300 MHz and 5.2 Gbps effective on the MI300.

The bus interface also differs: the MI300 uses PCIe 5.0 x16, while the Rubin uses PCIe 6.0 x16. Both GPUs have no display outputs, and both report N/A for DirectX, OpenGL, and Vulkan API support, confirming their compute-only orientation. The MI300 lists power connectors as 2x 8-pin, while the Rubin has no connector field recorded and comes as an SXM Module. The suggested PSU rating is 1000 W for the MI300 and 2700 W for the Rubin.

Power consumption differs by a factor of nearly four. The MI300 has a TDP of 600 W, while the Rubin is rated at 2300 W. The Rubin's much higher power envelope aligns with its higher clock ceiling and larger memory subsystem, but the data shows that the MI300 achieves its performance at significantly lower power draw.

The Verdict

The recorded data indicates that the NVIDIA Rubin GPU is the stronger part on nearly every compute metric. Its FP32 throughput of 130.0 TFLOPS is 2.7 times the MI300's 47.87 TFLOPS, and its FP16 output of 260.0 TFLOPS is more than five times the MI300's 47.87 TFLOPS. The Rubin also carries 2.04 times the shading units, 4.15 times the memory bandwidth, and 2.25 times the memory capacity of the MI300. For workloads that depend on FP16 tensor operations, the Rubin's 2:1 FP16 ratio versus the MI300's 1:1 ratio means the Rubin can process FP16 data at twice its FP32 rate, while the MI300 processes both at the same rate.

The AMD part does hold some advantages. The MI300 has a higher base clock (1000 MHz versus 700 MHz) and a lower TDP (600 W versus 2300 W). The MI300's power efficiency, as measured by performance per watt, is not directly comparable without benchmark scores, but the raw numbers show that the MI300 delivers 47.87 TFLOPS at 600 W, while the Rubin delivers 130.0 TFLOPS at 2300 W. The MI300's texture rate of 1,496.0 GTexel/s is only 26% lower than the Rubin's 2,031.2 GTexel/s, despite the Rubin having 16 more TMUs. The MI300 also has a longer physical footprint at 267 mm / 10.5 inches in length and 111 mm / 4.4 inches in height, while the Rubin has no dimensions recorded.

From a generation standpoint, the MI300 released on 2023-01-03, while the Rubin is dated 2025-12-31 with an Active production status. The MI300 lists no production status. The Rubin succeeds Server Blackwell, and the MI300 succeeds Radeon Instinct. Neither has a recorded successor.

The data supports a straightforward choice: the NVIDIA Rubin GPU is for workloads that need maximum FP32 or FP16 throughput, massive memory bandwidth, and high memory capacity. The AMD Instinct MI300 is for deployments where power draw, base clock stability, or the 8-pin power connector format are priorities, and where the compute demands stay within 47.87 TFLOPS FP32 or FP16.

Specification Differences

The following fields differ between the AMD Instinct MI300 and the NVIDIA Rubin GPU:

• Chip: Aqua Vanjaram versus GR100
• Architecture: CDNA 3.0 versus Rubin
• Generation: Instinct (MIx) versus Server Rubin (Rxx)
• Process Node: 5 nm versus 3 nm
• Foundry: TSMC (both, but listed separately)
• Transistors: 153,000 million versus 336,000 million
• Die Size: 1017 mm² versus 1456 mm²
• Transistor Density: 150.4M / mm² versus 230.8M / mm²
• Base Clock: 1000 MHz versus 700 MHz
• Boost Clock: 1700 MHz versus 2267 MHz
• Memory Clock: 1300 MHz 5.2 Gbps effective versus 2695 MHz 10.8 Gbps effective
• Memory Size: 128 GB versus 288 GB
• Memory Type: HBM3 versus HBM4
• Memory Bus Width: 8192 bit versus 16384 bit
• Memory Bandwidth: 5.32 TB/s versus 22.1 TB/s
• Shading Units: 14080 versus 28672
• TMUs: 880 versus 896
• ROPs: 0 versus 24
• Tensor Cores: null versus 896
• Pixel Rate: 0 MPixel/s versus 54.41 GPixel/s
• Texture Rate: 1,496.0 GTexel/s versus 2,031.2 GTexel/s
• FP32: 47.87 TFLOPS versus 130.0 TFLOPS
• FP16: 47.87 TFLOPS (1:1) versus 260.0 TFLOPS (2:1)
• TDP: 600 W versus 2300 W
• Slot Width: null versus SXM Module
• Power Connectors: 2x 8-pin versus null
• Suggested PSU: 1000 W versus 2700 W
• Bus Interface: PCIe 5.0 x16 versus PCIe 6.0 x16
• Dimensions: 267 mm length, 111 mm height versus null
• Release Date: 2023-01-03 versus 2025-12-31
• Production Status: null versus Active
• Predecessor: Radeon Instinct versus Server Blackwell

Fields that are identical include: manufacturer (each has its own), display outputs (No outputs for both), and all API support (N/A for DirectX, OpenGL, and Vulkan on both). No launch MSRP is recorded for either GPU.

FAQ

Q: Which GPU has higher FP32 performance?

A: The NVIDIA Rubin GPU delivers 130.0 TFLOPS FP32, which is 2.7 times the AMD Instinct MI300's 47.87 TFLOPS.

Q: How do the memory subsystems compare?

A: The Rubin uses HBM4 with 288 GB capacity, a 16384-bit bus, and 22.1 TB/s bandwidth. The MI300 uses HBM3 with 128 GB capacity, an 8192-bit bus, and 5.32 TB/s bandwidth. The Rubin has 4.15 times the bandwidth and 2.25 times the capacity.

Q: What is the difference in FP16 throughput?

A: The Rubin achieves 260.0 TFLOPS FP16 with a 2:1 ratio, while the MI300 achieves 47.87 TFLOPS FP16 with a 1:1 ratio. The Rubin's FP16 output is over five times higher.

Q: Which GPU has more shading units?

A: The Rubin has 28,672 shading units, more than double the MI300's 14,080. The Rubin also has 896 tensor cores, while the MI300 has no tensor core count recorded.

Q: How do power requirements differ?

A: The MI300 has a TDP of 600 W with a suggested PSU of 1000 W and 2x 8-pin connectors. The Rubin has a TDP of 2300 W with a suggested PSU of 2700 W and no connector field recorded, listed as an SXM Module.

Q: Do either GPUs support display outputs?

A: No. Both the AMD Instinct MI300 and the NVIDIA Rubin GPU record "No outputs" for display connections, and both report N/A for DirectX, OpenGL, and Vulkan API support.