AMD Instinct MI300X vs AMD Radeon RX 6650M XT Comparison

The Verdict

The recorded data presents a stark contrast between two AMD accelerators designed for entirely different roles. The AMD Instinct MI300X is a data center compute module with a Geekbench OpenCL score of 317,994, placing it in the 100th percentile of all GPUs. The AMD Radeon RX 6650M XT is a mobile graphics processor with a score of 76,904, sitting in the 91st percentile. For any workload captured by this benchmark, the Instinct MI300X is the clear choice. It outperforms the RX 6650M XT by 313.5% in the single recorded head-to-head test. The RX 6650M XT wins no benchmark comparisons in the database. Users requiring massive compute throughput for servers or scientific workloads should select the Instinct MI300X. Users needing a mobile, integrated graphics solution for a portable device have only the RX 6650M XT as an option between these two, but the data shows no performance scenario where it is preferable.

Architecture Differences

The two processors come from different AMD lineages, built on distinct process nodes. The Instinct MI300X uses the CDNA 3.0 architecture, while the RX 665M XT uses RDNA 2.0. The manufacturing process differs significantly: the MI300X is built on a 5 nm node, whereas the RX 6650M XT uses a 7 nm node. Both are fabricated by TSMC, but the transistor counts and die sizes diverge sharply. The MI300X packs 153,000 million transistors on a 1017 mm² die, resulting in a transistor density of 150.4 million per mm². The RX 6650M XT contains 11,060 million transistors on a 237 mm² die, with a density of 46.7 million per mm². This means the Instinct chip is roughly an order of magnitude larger in both die area and transistor count.

The memory subsystems are also fundamentally different. The MI300X uses 192 GB of HBM3 memory on a 8192-bit bus, delivering 5.32 TB/s of bandwidth. The RX 6650M XT uses 8 GB of GDDR6 on a 128-bit bus, providing 256.0 GB/s. Clock speeds show a different trade-off: the MI300X has a base clock of 1000 MHz and a boost of 2100 MHz, while the RX 6650M XT operates at a base of 2068 MHz, a game clock of 2162 MHz, and a boost of 2416 MHz. Despite lower clocks, the MI300X achieves far higher throughput due to its massive shading unit count: 19,456 versus 2,048 for the RX 6650M XT. Texture mapping units number 1,216 on the MI300X versus 128 on the RX 6650M XT. The RX 6650M XT has 64 ROPs and 32 ray tracing cores; the MI300X has 0 ROPs and no listed ray tracing cores. The MI300X has no display outputs, while the RX 6650M XT has outputs dependent on the portable device. Power consumption differs by a factor of over six: the MI300X has a TDP of 750 W, while the RX 6650M XT has a TDP of 120 W.

Where Each One Wins

The benchmark data records only a single comparison test: Geekbench OpenCL. In that test, the Instinct MI300X is the winner with a delta of 313.5% over the RX 6650M XT. The MI300X also holds the top percentile position, ranking in the 100th percentile of all GPUs, while the RX 6650M XT ranks in the 91st percentile. The MI300X's nearest rivals in the database are other data center accelerators: the NVIDIA H200 NVL scores 334,891 (5% higher), the NVIDIA L40S scores 295,763 (7.5% lower), the NVIDIA B200 scores 345,482 (8% higher), and the NVIDIA RTX 6000 Ada Generation scores 287,237 (10.7% lower). In this context, the MI300X sits in a competitive band among top-tier compute accelerators, slightly behind the H200 and B200 but ahead of the L40S and RTX 6000 Ada.

The RX 6650M XT's nearest rivals are a different class entirely: the NVIDIA GeForce RTX 5090 D scores 77,712 (1% higher), the AMD Radeon RX 6850M XT scores 78,940 (2.6% higher), the NVIDIA Tesla P100 PCIe 12 GB scores 79,396 (3.1% higher), and the NVIDIA Tesla P100 PCIe 16 GB scores 79,605 (3.4% higher). The RX 6650M XT is the lowest-scoring among its immediate rivals, trailing each by small margins. There is no recorded benchmark where the RX 6650M XT beats the MI300X. For general compute tasks in OpenCL, the MI300X is overwhelmingly faster. For mobile gaming or graphics workloads, the RX 6650M XT has the architectural features for that role, but no benchmark data in the database supports a win over the MI300X.

FAQ

Q: How much faster is the AMD Instinct MI300X than the AMD Radeon RX 6650M XT in OpenCL?

A: The MI300X scores 317,994 versus 76,904 for the RX 6650M XT, a delta of 313.5% in favor of the Instinct card.

Q: Which GPU has a higher memory bandwidth?

A: The Instinct MI300X has a memory bandwidth of 5.32 TB/s using HBM3 on a 8192-bit bus. The RX 6650M XT has 256.0 GB/s using GDDR6 on a 128-bit bus.

Q: What are the process nodes for these two chips?

A: The MI300X is built on a 5 nm TSMC process, while the RX 6650M XT is on a 7 nm TSMC process.

Q: Does the RX 6650M XT have any ray tracing capability?

A: Yes, the RX 6650M XT has 32 ray tracing cores. The MI300X has no listed ray tracing cores.

Q: What is the TDP difference between the two?

A: The MI300X has a TDP of 750 W, while the RX 6650M XT has a TDP of 120 W.

Q: Which GPU has more shading units?

A: The MI300X has 19,456 shading units, compared to 2,048 on the RX 6650M XT.

Head-to-Head Benchmarks

The database records one head-to-head benchmark between these two processors: Geekbench OpenCL. The Instinct MI300X achieves a score of 317,994, while the RX 6650M XT achieves 76,904. The MI300X wins this test by a delta of 313.5%. This is a massive margin, indicating that the MI300X delivers over four times the OpenCL performance of the RX 6650M XT. The wins count is 1 for the MI300X and 0 for the RX 6650M XT.

To contextualize the MI300X's score, it ranks in the 100th percentile of all GPUs, meaning it scores at or above nearly every other recorded GPU. Its nearest rival, the NVIDIA H200 NVL, scores 334,891, which is 5% higher. The NVIDIA B200 scores 345,482, 8% higher. However, the MI300X beats the NVIDIA L40S (295,763, 7.5% lower) and the NVIDIA RTX 6000 Ada Generation (287,237, 10.7% lower). The RX 6650M XT, at 76,904, is in the 91st percentile. Its nearest rival, the NVIDIA GeForce RTX 5090 D, scores 77,712, just 1% higher. The AMD Radeon RX 6850M XT scores 78,940 (2.6% higher), the NVIDIA Tesla P100 PCIe 12 GB scores 79,396 (3.1% higher), and the NVIDIA Tesla P100 PCIe 16 GB scores 79,605 (3.4% higher). The RX 6650M XT trails all four of its nearest rivals by small single-digit percentages.

The texture rates further illustrate the gap. The MI300X has a texture rate of 2,553.6 GTexel/s, while the RX 6650M XT has 309.2 GTexel/s. The pixel rate for the MI300X is 0 MPixel/s due to having no ROPs, while the RX 6650M XT has a pixel rate of 154.6 GPixel/s. Floating-point performance shows the MI300X at 81.72 TFLOPS for FP32 and 81.72 TFLOPS for FP16 (1:1 ratio). The RX 6650M XT delivers 9.896 TFLOPS for FP32 and 19.79 TFLOPS for FP16 (2:1 ratio). These figures align with the benchmark outcome: the MI300X is designed for raw compute density, and the RX 6650M XT is a lower-power mobile part.

Specification Differences

The two processors differ in nearly every measurable specification. The MI300X uses the Aqua Vanjaram chip, while the RX 6650M XT uses the Navi 23 chip. The MI300X belongs to the Instinct (MIx) generation; the RX 6650M XT is part of the Navi Mobile (RX 6000M) generation. The process node is 5 nm for the MI300X and 7 nm for the RX 6650M XT. Transistor counts are 153,000 million versus 11,060 million. Die size is 1017 mm² versus 237 mm². Transistor density is 150.4 million per mm² versus 46.7 million per mm².

Clock speeds differ: the MI300X has a base of 1000 MHz and boost of 2100 MHz, while the RX 6650M XT has a base of 2068 MHz, game clock of 2162 MHz, and boost of 2416 MHz. Memory specifications are entirely different: the MI300X has 192 GB of HBM3 with a 8192-bit bus and 5.32 TB/s bandwidth, while the RX 6650M XT has 8 GB of GDDR6 with a 128-bit bus and 256.0 GB/s bandwidth. The memory clock for the MI300X is 1300 MHz (5.2 Gbps effective), whereas the RX 6650M XT runs at 2000 MHz (16 Gbps effective).

Compute unit counts diverge: the MI300X has 19,456 shading units, 1,216 TMUs, and 0 ROPs. The RX 6650M XT has 2,048 shading units, 128 TMUs, and 64 ROPs. Ray tracing cores are absent on the MI300X but present on the RX 6650M XT with 32 cores. Pixel rates are 0 MPixel/s for the MI300X and 154.6 GPixel/s for the RX 6650M XT. Texture rates are 2,553.6 GTexel/s versus 309.2 GTexel/s. FP32 performance is 81.72 TFLOPS versus 9.896 TFLOPS. FP16 performance is 81.72 TFLOPS (1:1) versus 19.79 TFLOPS (2:1).

Power and form factor: the MI300X has a TDP of 750 W and is an OAM Module with no power connectors and a suggested PSU of 1150 W. The RX 6650M XT has a TDP of 120 W, is an IGP, has no power connectors, and no suggested PSU. The bus interface is PCIe 5.0 x16 for the MI300X and PCIe 4.0 x8 for the RX 6650M XT. Display outputs: the MI300X has none, while the RX 6650M XT has outputs dependent on the portable device. API support differs: the MI300X has no DirectX, OpenGL, or Vulkan support, while the RX 6650M XT supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. Release dates are 2023-12-05 for the MI300X and 2022-01-03 for the RX 6650M XT. The production status of the RX 6650M XT is end-of-life; no status is recorded for the MI300X.