AMD Instinct MI300 vs AMD Radeon RX 6550S Comparison

The Verdict

The recorded data presents two AMD accelerators with completely divergent design philosophies, yet both occupy the 50th percentile in the database. The AMD Instinct MI300 is a data center compute accelerator with no display outputs, a 600 W power envelope, and 128 GB of HBM3 memory. The AMD Radeon RX 6550S is a mobile graphics processor with a 50 W power envelope, 4 GB of GDDR6 memory, and portable device dependent display outputs. The benchmark results show zero wins for either part, which indicates the database contains no recorded performance measurements for these two specific SKUs. The practical verdict is that the MI300 serves compute workloads requiring massive memory bandwidth and throughput, while the RX 6550S serves mobile graphics tasks within a constrained power budget.

Architecture Differences

The MI300 uses the Aqua Vanjaram chip built on TSMC's 5 nm process, featuring CDNA 3.0 architecture. The RX 6550S uses the Navi 24 chip built on TSMC's 6 nm process, featuring RDNA 2.0 architecture. The transistor counts differ by a factor of roughly 28: the MI300 integrates 153,000 million transistors across a 1017 mm² die, while the RX 6550S integrates 5,400 million transistors on a 107 mm² die. Transistor density reflects this: the MI300 achieves 150.4M transistors per mm², while the RX 6550S achieves 50.5M per mm².

The MI300 belongs to the Instinct (MIx) generation, while the RX 6550S belongs to the Navi Mobile (RX 6000M) generation. The MI300's predecessor is Radeon Instinct, and the RX 6550S's predecessor is Polaris Mobile. Both parts share a release date of January 3, 2023. The MI300's production status is not recorded, while the RX 6550S is marked as Active.

Shading unit counts show the scale difference: the MI300 has 14,080 shading units, 880 texture mapping units, and 0 ROPs. The RX 6550S has 1,024 shading units, 64 texture mapping units, and 32 ROPs. The MI300 has no recorded RT cores, while the RX 6550S has 16 RT cores. Neither part lists tensor cores in the database.

Where Each One Wins

Without recorded benchmark scores, the wins must be inferred from architectural specifications. The MI300 wins in raw compute throughput: its FP32 performance is 47.87 TFLOPS, which is approximately 9.7 times higher than the RX 6550S's 4.915 TFLOPS. The MI300's FP16 performance matches its FP32 at 47.87 TFLOPS with a 1:1 ratio, while the RX 6550S achieves 9.830 TFLOPS FP16 with a 2:1 ratio, meaning the MI300 delivers roughly 4.9 times the FP16 throughput.

Memory capacity and bandwidth favor the MI300 decisively. The MI300 offers 128 GB of HBM3 on an 8192-bit bus, delivering 5.32 TB/s of bandwidth. The RX 6550S offers 4 GB of GDDR6 on a 64-bit bus, delivering 128.0 GB/s. That represents a 32-fold capacity advantage and a 41.5-fold bandwidth advantage for the MI300. The RX 6550S wins in efficiency metrics: its 50 W TDP versus the MI300's 600 W TDP means the mobile part draws 8.3 percent of the power while delivering roughly 10.2 percent of the FP32 performance, suggesting better performance per watt in FP32. The RX 6550S also wins in practical graphics features: it supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the MI300 lists N/A for all graphics APIs and provides no display outputs.

FAQ

Q: Why does the AMD Instinct MI300 have zero ROPs?

A: The database records the MI300's pixel rate as 0 MPixel/s with 0 ROPs. This indicates the accelerator is not designed for rasterized graphics output, consistent with its "No outputs" display configuration.

Q: What is the memory bandwidth difference between the two cards?

A: The MI300 provides 5.32 TB/s of bandwidth using HBM3 memory on an 8192-bit bus. The RX 6550S provides 128.0 GB/s using GDDR6 on a 64-bit bus. The MI300's bandwidth is 41.5 times higher.

Q: Which card supports ray tracing?

A: The RX 6550S includes 16 RT cores. The MI300 has no recorded RT cores in the database.

Q: How do the power requirements differ?

A: The MI300 has a 600 W TDP with 2x 8-pin power connectors and a suggested 1000 W power supply. The RX 6550S has a 50 W TDP with no power connectors listed and no suggested PSU, marked as an integrated graphics processor.

Q: Are both cards from the same manufacturing process?

A: No. The MI300 uses a 5 nm TSMC process, while the RX 6550S uses a 6 nm TSMC process. Both are fabricated by TSMC.

Q: What does the 50th percentile ranking mean for these GPUs?

A: Both parts are recorded at the 50th percentile versus all GPUs in the database. With no benchmark scores and no nearest rivals listed, this percentile reflects their relative standing based on the available data, which includes no performance measurements.

Head-to-Head Benchmarks

The database records zero head-to-head benchmark entries, zero wins for the MI300, and zero wins for the RX 6550S. The absence of measured performance data means direct comparisons must rely entirely on specification sheets. The largest recorded advantage belongs to the MI300 in memory bandwidth: 5.32 TB/s versus 128.0 GB/s, a 41.5-fold difference. The FP32 compute gap is also substantial: 47.87 TFLOPS versus 4.915 TFLOPS, which is 9.7 times higher on the MI300. The texture rate favors the MI300 at 1,496.0 GTexel/s versus 153.6 GTexel/s, a 9.7-fold advantage that mirrors the shading unit ratio of 14,080 versus 1,024, which is 13.75 times higher.

The RX 6550S counters with a pixel rate of 76.80 GPixel/s, while the MI300 records 0 MPixel/s. The RX 6550S also leads in clock speeds: its base clock is 2000 MHz versus 1000 MHz, and its boost clock is 2400 MHz versus 1700 MHz. The game clock of 2170 MHz on the RX 6550S has no equivalent on the MI300. The RX 6550S achieves its FP16 performance at 9.830 TFLOPS, which is 2 times its FP32 rate, while the MI300's FP16 matches its FP32 at 47.87 TFLOPS. The RX 6550S's memory clock runs at 2000 MHz with 16 Gbps effective, while the MI300's memory clock is 1300 MHz with 5.2 Gbps effective. The MI300's higher effective memory speed, combined with its 8192-bit bus width, produces the bandwidth advantage noted above.

The transistor density comparison is informative: the MI300 packs 150.4 million transistors per mm², while the RX 6550S achieves 50.5 million per mm². That 3.0-fold density difference reflects the more advanced 5 nm process and the larger, more complex die. The MI300's 1017 mm² die is 9.5 times larger than the RX 6550S's 107 mm² die, yet the transistor count is 28.3 times higher, indicating the density advantage compounds with die size.

Specification Differences

The two parts differ across nearly every recorded specification field. The MI300 uses the Aqua Vanjaram chip with CDNA 3.0 architecture, while the RX 6550S uses Navi 24 with RDNA 2.0. The process nodes differ: 5 nm versus 6 nm. Transistor counts are 153,000 million versus 5,400 million. Die sizes are 1017 mm² versus 107 mm². Transistor densities are 150.4M per mm² versus 50.5M per mm².

Clock specifications diverge significantly. The MI300 has a 1000 MHz base and 1700 MHz boost. The RX 6550S has a 2000 MHz base, 2400 MHz boost, and a 2170 MHz game clock. Memory clocks are 1300 MHz with 5.2 Gbps effective on the MI300, versus 2000 MHz with 16 Gbps effective on the RX 6550S. Memory configurations differ entirely: 128 GB HBM3 on an 8192-bit bus versus 4 GB GDDR6 on a 64-bit bus. Bandwidth is 5.32 TB/s versus 128.0 GB/s.

Compute resources differ in scale: 14,080 shading units versus 1,024; 880 TMUs versus 64; 0 ROPs versus 32. The RX 6550S has 16 RT cores; the MI300 has none recorded. Pixel rates are 0 MPixel/s versus 76.80 GPixel/s. Texture rates are 1,496.0 GTexel/s versus 153.6 GTexel/s. FP32 performance is 47.87 TFLOPS versus 4.915 TFLOPS. FP16 performance is 47.87 TFLOPS (1:1) versus 9.830 TFLOPS (2:1).

Power and physical characteristics differ completely. The MI300 has a 600 W TDP, 2x 8-pin power connectors, a suggested 1000 W PSU, and dimensions of 267 mm length by 111 mm height. The RX 6550S has a 50 W TDP, no power connectors, no suggested PSU, and no recorded dimensions, with a slot width marked as IGP. The MI300 uses PCIe 5.0 x16, while the RX 6550S uses PCIe 4.0 x4. Display outputs are "No outputs" on the MI300 versus "Portable Device Dependent" on the RX 6550S. The MI300 lists N/A for DirectX, OpenGL, and Vulkan support, while the RX 6550S supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI300's production status is unrecorded; the RX 6550S is Active. Both share the same release date and neither has a successor recorded.