GPU Comparison

# AMD Instinct MI300X vs AMD Radeon PRO V620

The AMD Instinct MI300X and AMD Radeon PRO V620 occupy entirely different tiers of the AMD accelerator stack, and the benchmark data makes the separation unambiguous. Across the single shared benchmark (Geekbench OpenCL), the MI300X scores 317,994 against 128,580 for the V620, a 147.3% advantage. The MI300X sits at the 100th percentile of all GPUs, while the V620 sits at the 96th. These are not competing products; they are solutions for different classes of workloads, with the MI300X targeting large-scale compute and the V620 serving as a more modest, legacy-oriented option.

The Verdict

The data points to one clear conclusion: choose the AMD Instinct MI300X if your work demands maximum compute throughput and memory capacity. Its Geekbench OpenCL score of 317,994 is more than double the V620's 128,580, placing it at the absolute top of the GPU hierarchy (100th percentile). The MI300X also benefits from a 192 GB HBM3 memory pool with 5.32 TB/s bandwidth, making it suited for massive datasets that would never fit in the V620's 32 GB GDDR6 allocation. For anyone running large-scale AI inference, scientific simulation, or data-parallel workloads where memory capacity and raw FP32/FP16 throughput are the bottlenecks, the MI300X is the only rational pick from these two.

The AMD Radeon PRO V620, by contrast, is the choice only when the workload is smaller, the power envelope is tighter, and the requirement for advanced graphics APIs matters. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, whereas the MI300X reports N/A for all graphics APIs. The V620 also has a 300 W TDP versus 750 W for the MI300X, and it uses standard PCIe 4.0 x16 with dual-slot cooling and 2x 8-pin power connectors, a far more conventional installation profile than the MI300X's OAM module form factor. If a system cannot accommodate an OAM card and needs a drop-in PCIe accelerator with graphics API support, the V620 is the practical fallback, provided its 32 GB memory and 20.28 TFLOPS FP32 are sufficient.

However, the V620 is end-of-life, and its performance class is crowded: it sits within 0.9% of several rivals (AMD Radeon Pro W6800X Duo at 0.5%, AMD Radeon PRO W6800 at 0.8%, NVIDIA A10M at 0.9%, NVIDIA RTX 4000 Ada Generation at 0.9%). The MI300X, on the other hand, leads its nearest rivals by significant margins, 7.5% over the NVIDIA L40S and 10.7% over the NVIDIA RTX 6000 Ada Generation, while trailing the NVIDIA H200 NVL by 5% and the B200 by 8%. For new deployments, the MI300X is clearly the forward-looking choice; the V620 is a legacy part that only makes sense for specific compatibility needs.

FAQ

Q: Which GPU has a higher Geekbench OpenCL score?

A: The AMD Instinct MI300X scores 317,994, which is 147.3% higher than the Radeon PRO V620's 128,580. The MI300X also achieves a 100th percentile ranking versus the V620's 96th.

Q: How do the memory configurations differ?

A: The MI300X has 192 GB of HBM3 with an 8192-bit bus and 5.32 TB/s bandwidth. The V620 has 32 GB of GDDR6 with a 256-bit bus and 512.0 GB/s bandwidth. The MI300X offers 6x the capacity and roughly 10.4x the bandwidth.

Q: Do both cards support graphics APIs?

A: No. The Radeon PRO V620 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The Instinct MI300X reports N/A for DirectX, OpenGL, and Vulkan, indicating no graphics API support.

Q: What are the power and form factor differences?

A: The MI300X has a 750 W TDP and uses an OAM module slot with no power connectors (power delivered via the module interface). The V620 has a 300 W TDP, is dual-slot, uses 2x 8-pin power connectors, and requires a 700 W suggested PSU versus 1150 W for the MI300X.

Q: Which card is newer and what is its production status?

A: The MI300X was released on 2023-12-05 and is based on CDNA 3.0 architecture (chip: Aqua Vanjaram). The V620 was released on 2021-11-03, is based on RDNA 2.0 (chip: Navi 21), and is marked as end-of-life.

Q: How does the MI300X compare to its nearest rivals?

A: The MI300X is 7.5% ahead of the NVIDIA L40S (295,763) and 10.7% ahead of the NVIDIA RTX 6000 Ada Generation (287,237). It trails the NVIDIA H200 NVL (334,891) by 5% and the NVIDIA B200 (345,482) by 8%.

Architecture Differences

The architectural divide between these two AMD accelerators is fundamental. The MI300X uses CDNA 3.0 architecture, designed specifically for compute workloads, built on a 5 nm TSMC process with 153,000 million transistors on a 1017 mm² die. The V620 uses RDNA 2.0, a graphics-oriented architecture, on a 7 nm TSMC process with 26,800 million transistors on a 520 mm² die. This results in a transistor density of 150.4M per mm² for the MI300X versus 51.5M per mm² for the V620, a nearly 3x density advantage for the newer part.

The MI300X has 19,456 shading units and 1,216 TMUs, but reports 0 ROPs and a pixel rate of 0 MPixel/s, confirming it has no rasterization pipeline. It also reports no RT cores and no tensor cores (though CDNA 3.0 includes matrix cores, they are not exposed in this data). The V620 has 4,608 shading units, 288 TMUs, 128 ROPs, and 72 RT cores, with a pixel rate of 281.6 GPixel/s. The V620's texture rate is 633.6 GTexel/s versus 2,553.6 GTexel/s for the MI300X, a 4x difference in texture throughput.

Memory architecture is equally divergent. The MI300X uses HBM3 with an 8192-bit bus, achieving 5.32 TB/s bandwidth, while the V620 uses GDDR6 with a 256-bit bus, achieving 512.0 GB/s. The FP32 compute figures tell the story: the MI300X delivers 81.72 TFLOPS versus 20.28 TFLOPS for the V620. For FP16, the MI300X again delivers 81.72 TFLOPS (1:1 ratio), while the V620 delivers 40.55 TFLOPS (2:1 ratio). The MI300X's FP16 performance is exactly 2x the V620's, but the MI300X maintains that throughput at FP32 while the V620 drops by half.

The MI300X uses a PCIe 5.0 x16 interface and has no display outputs, matching the V620's no-output design. The V620's PCIe 4.0 x16 interface is one generation older. The MI300X's OAM module form factor (with no power connectors) reflects its data-center design, while the V620's dual-slot, 2x 8-pin configuration is more traditional workstation-oriented.

Specification Differences

The specification sheet shows few shared fields. Process node: 5 nm (MI300X) versus 7 nm (V620). Transistors: 153,000 million versus 26,800 million. Die size: 1017 mm² versus 520 mm². Transistor density: 150.4M/mm² versus 51.5M/mm². Base clock: 1000 MHz versus 1825 MHz. Boost clock: 2100 MHz versus 2200 MHz. Memory clock: 1300 MHz (5.2 Gbps effective) versus 2000 MHz (16 Gbps effective).

Memory: 192 GB HBM3 versus 32 GB GDDR6. Bus width: 8192 bit versus 256 bit. Bandwidth: 5.32 TB/s versus 512.0 GB/s. Shading units: 19,456 versus 4,608. TMUs: 1,216 versus 288. ROPs: 0 versus 128. RT cores: not listed versus 72. Pixel rate: 0 MPixel/s versus 281.6 GPixel/s. Texture rate: 2,553.6 GTexel/s versus 633.6 GTexel/s. FP32: 81.72 TFLOPS versus 20.28 TFLOPS. FP16: 81.72 TFLOPS (1:1) versus 40.55 TFLOPS (2:1).

TDP: 750 W versus 300 W. Slot width: OAM Module versus Dual-slot. Power connectors: None versus 2x 8-pin. Suggested PSU: 1150 W versus 700 W. Bus interface: PCIe 5.0 x16 versus PCIe 4.0 x16. Display outputs: No outputs for both. DirectX: N/A versus 12 Ultimate (12_2). OpenGL: N/A versus 4.6. Vulkan: N/A versus 1.4. Dimensions: the MI300X has no listed dimensions, while the V620 measures 267 mm (10.5 inches) in length, 120 mm (4.7 inches) in height, and 50 mm (2 inches) in width. Release dates: 2023-12-05 versus 2021-11-03. Production status: not listed for MI300X, end-of-life for V620. Predecessors: Radeon Instinct versus Radeon Pro Vega.

Head-to-Head Benchmarks

The only directly comparable benchmark is Geekbench OpenCL, and the result is decisive. The MI300X scores 317,994 against the V620's 128,580, a delta of 147.3% in favor of the MI300X. This means the MI300X achieves approximately 2.47x the raw OpenCL performance of the V620. The MI300X also has a Vulkan benchmark listed (144,364), but the MI300X has no Vulkan result, consistent with its N/A Vulkan API status.

Looking at the MI300X's nearest rivals provides context for its OpenCL score. It beats the NVIDIA L40S (295,763) by 7.5% and the NVIDIA RTX 6000 Ada Generation (287,237) by 10.7%. It trails the NVIDIA H200 NVL (334,891) by 5% and the NVIDIA B200 (345,482) by 8%. The V620's nearest rivals are much closer: it is 0.5% ahead of the AMD Radeon Pro W6800X Duo (135,774), 0.8% ahead of the AMD Radeon PRO W6800 (135,396), 0.9% ahead of the NVIDIA A10M (135,230), and 0.9% ahead of the NVIDIA RTX 4000 Ada Generation (135,218). The V620's performance is effectively at parity with its peer group, while the MI300X sits in a different league entirely.

The average benchmark score tells the same story: the MI300X averages 317,994 (from a single OpenCL result), while the V620 averages 136,472 (from two results: 128,580 OpenCL and 144,364 Vulkan). Even the V620's stronger Vulkan score is less than half the MI300X's OpenCL score.

Where Each One Wins

The AMD Instinct MI300X wins decisively in raw compute performance. Its 147.3% OpenCL lead over the V620 makes it the obvious choice for any workload that is bottlenecked by FP32 or FP16 throughput. The 192 GB HBM3 memory with 5.32 TB/s bandwidth is a massive win for large-batch AI training, inference on large models, and scientific computing where datasets exceed 32 GB. The 100th percentile ranking means it is at the top of the entire GPU population in this benchmark database. The MI300X also wins on transistor density (150.4M/mm² versus 51.5M/mm²) and texture rate (2,553.6 GTexel/s versus 633.6 GTexel/s), though the latter is less relevant given its lack of a raster pipeline.

The AMD Radeon PRO V620 wins in areas that matter for specific deployments. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, making it usable for compute workloads that also require graphics API features, the MI300X has no graphics API support. The V620's 72 RT cores and 128 ROPs enable ray tracing and rasterization, which the MI300X cannot do. The V620's 300 W TDP and 700 W suggested PSU make it compatible with standard workstation power supplies, while the MI300X requires an OAM slot and 1150 W PSU. The V620's dual-slot, 2x 8-pin form factor fits in conventional server chassis, whereas the MI300X's OAM module is a specialized data-center form factor. The V620's higher base clock (1825 MHz versus 1000 MHz) and boost clock (2200 MHz versus 2100 MHz) indicate better frequency behavior per watt, though its total throughput is far lower.

For compute density, the MI300X is the winner without qualification. For legacy compatibility, graphics API support, or power-constrained environments, the V620 retains a niche, but its end-of-life status and 96th percentile ranking suggest it is not a long-term investment. The data is clear: the MI300X is a top-tier compute accelerator, while the V620 is a mid-range part whose best days are behind it.