AMD Radeon Instinct MI25 vs AMD Radeon PRO V620 Comparison

Head-to-Head Benchmarks

The recorded database includes a single direct comparison between these two accelerators, the Geekbench OpenCL test. In this measurement, the AMD Radeon PRO V620 scores 128,580 points against the AMD Radeon Instinct MI25's 68,562 points. The delta is 87.5%, meaning the PRO V620 outperforms the MI25 by nearly nine-tenths in this compute workload. This is a decisive margin, not an incremental one.

Looking at the broader context, the PRO V620's average benchmark score sits at 136,472, placing it in the 96th percentile of all GPUs in the database. Its nearest rivals are all within one point of its average score: the AMD Radeon Pro W6800X Duo at 135,774 (0.5% behind), the AMD Radeon PRO W6800 at 135,396 (0.8% behind), and both the NVIDIA A10M and NVIDIA RTX 4000 Ada Generation at 135,230 and 135,218 respectively (0.9% behind). The PRO V620 essentially trades blows with these contemporary workstation cards, edging them out by less than a single percentage point.

The MI25, by contrast, averages 68,562 points and sits in the 90th percentile. Its nearest rivals are also tightly clustered: the Intel Arc A770 at 68,809 (0.4% ahead), the NVIDIA CMP 90HX at 69,000 (0.6% ahead), the AMD Radeon Pro WX 8200 at 69,870 (1.9% ahead), and the NVIDIA Quadro P6000 at 69,986 (2.0% ahead). The MI25 trails all four of its closest competitors, though the gaps are small, especially against the Intel and NVIDIA CMP parts.

The single head-to-head result aligns with these averages. The PRO V620's OpenCL score of 128,580 is close to its average of 136,472 but slightly below it, indicating that the OpenCL workload is not its strongest suite. The MI25's OpenCL score of 68,562 exactly matches its average, meaning this test is representative of its overall performance profile. When comparing the two directly, the PRO V620's advantage is substantial: it delivers roughly 1.9 times the OpenCL performance of the MI25.

This gap is not surprising given the architectural differences detailed in the specification sections below, but the magnitude of the delta is worth emphasizing. An 87.5% improvement in a compute benchmark is a generational leap, not a minor revision.

The Verdict

The data points to a clear hierarchy. The AMD Radeon PRO V620 wins the only direct benchmark comparison, and it does so by a wide margin. Its average score is nearly double that of the MI25, and its percentile ranking (96th versus 90th) reflects a higher tier of overall performance.

For users choosing between these two cards strictly from the recorded measurements, the PRO V620 is the superior compute device. It offers higher OpenCL throughput, better FP32 and FP16 performance (20.28 TFLOPS versus 12.29 TFLOPS, and 40.55 TFLOPS versus 24.58 TFLOPS respectively), and double the memory capacity at 32 GB versus 16 GB. The PRO V620 also supports DirectX 12 Ultimate, while the MI25 caps at DirectX 12 (12_1), and the PRO V620's Vulkan support is version 1.4 versus 1.3 on the MI25.

The MI25 is not without merit. Its 2048-bit HBM2 memory bus provides 436.2 GB/s of bandwidth, which is respectable, though the PRO V620's 512.0 GB/s is higher. Both cards share the same 300 W TDP, the same dual-slot design, and the same 2x 8-pin power connector requirement. For workloads that are sensitive to memory bandwidth rather than raw compute throughput, the MI25's HBM2 implementation might still be competitive, but the recorded benchmark data does not support that conclusion. The OpenCL test heavily favors the PRO V620.

In summary, the PRO V620 is the pick for anyone prioritizing compute performance, newer architecture support, and larger memory capacity. The MI25 is an older, slower part that, based on the data, should only be considered if the specific HBM2 memory characteristics are irreplaceable, a scenario not represented in the available benchmarks.

FAQ

Q: How much faster is the AMD Radeon PRO V620 than the MI25 in OpenCL?

A: The PRO V620 scores 128,580 in Geekbench OpenCL, while the MI25 scores 68,562. This is an 87.5% advantage for the PRO V620.

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

A: The PRO V620 has 32 GB of GDDR6 memory, while the MI25 has 16 GB of HBM2 memory. The PRO V620 also has higher bandwidth at 512.0 GB/s versus 436.2 GB/s.

Q: Which card has a higher average benchmark score?

A: The PRO V620 averages 136,472 points across all recorded benchmarks, placing it in the 96th percentile. The MI25 averages 68,562 points, placing it in the 90th percentile.

Q: Do both cards consume the same power?

A: Yes, both have a 300 W TDP, both are dual-slot designs, and both require 2x 8-pin power connectors. The suggested power supply is 700 W for each.

Q: Which card supports newer graphics APIs?

A: The PRO V620 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI25 supports DirectX 12 (12_1), OpenGL 4.6, and Vulkan 1.3.

Q: What are the release dates for these two GPUs?

A: The PRO V620 was released on November 3, 2021. The MI25 was released on June 26, 2017. Both are now end-of-life products.

Specification Differences

The two accelerators differ in nearly every core specification. The PRO V620 uses the Navi 21 chip with an RDNA 2.0 architecture, while the MI25 uses the Vega 10 chip with a GCN 5.0 architecture. The PRO V620 is built on a 7 nm process at TSMC, whereas the MI25 uses a 14 nm process at GlobalFoundries.

The PRO V620 has 4,608 shading units, 288 texture mapping units, and 128 render output units. The MI25 has 4,096 shading units, 256 TMUs, and 64 ROPs. The PRO V620 also includes 72 ray tracing cores, which the MI25 lacks entirely.

Clock speeds differ significantly: the PRO V620 runs at a base of 1825 MHz and boosts to 2200 MHz, while the MI25 runs at a base of 1400 MHz and boosts to 1500 MHz. Memory clocks are also different: the PRO V620 uses 2000 MHz (16 Gbps effective) GDDR6, while the MI25 uses 852 MHz (1704 Mbps effective) HBM2.

The PRO V620's memory bus is 256-bit, compared to the MI25's 2048-bit bus. Despite the narrower bus, the PRO V620 achieves higher bandwidth (512.0 GB/s versus 436.2 GB/s) due to its faster memory clock. The PRO V620 also has a higher transistor count (26,800 million versus 12,500 million) and a larger die size (520 mm² versus 495 mm²), with a transistor density of 51.5M per mm² versus 25.3M per mm².

Pixel and texture rates follow the same pattern: the PRO V620 delivers 281.6 GPixel/s and 633.6 GTexel/s, while the MI25 delivers 96.00 GPixel/s and 384.0 GTexel/s. FP32 compute is 20.28 TFLOPS for the PRO V620 versus 12.29 TFLOPS for the MI25, and FP16 is 40.55 TFLOPS versus 24.58 TFLOPS, both at a 2:1 ratio.

The PRO V620 uses PCIe 4.0 x16, while the MI25 uses PCIe 3.0 x16. Physical dimensions are similar in length (267 mm for both), but the PRO V620 is taller at 120 mm versus 111 mm, and it has a width of 50 mm, while the MI25's width is not recorded.

Architecture Differences

The architectural gap between these two cards is substantial. The PRO V620 is built on RDNA 2.0, AMD's modern gaming and compute architecture, while the MI25 uses GCN 5.0, an older design originally developed for Vega-era products. This generational difference explains much of the performance delta.

The process node difference is stark: 7 nm at TSMC for the PRO V620 versus 14 nm at GlobalFoundries for the MI25. This allows the PRO V620 to pack 26,800 million transistors into a 520 mm² die, achieving a density of 51.5M per mm². The MI25, by contrast, fits 12,500 million transistors into a 495 mm² die, at a density of 25.3M per mm². The PRO V620 nearly doubles the transistor density, which directly enables its higher clock speeds and greater compute throughput.

The PRO V620 includes 72 ray tracing cores, a feature completely absent from the MI25. This makes the PRO V620 capable of hardware-accelerated ray tracing, while the MI25 would need to rely on software or compute-based approaches. The PRO V620 also supports DirectX 12 Ultimate, which includes features like variable rate shading and mesh shaders, while the MI25 is limited to DirectX 12 (12_1).

Memory architecture differs fundamentally. The PRO V620 uses 32 GB of GDDR6 on a 256-bit bus, while the MI25 uses 16 GB of HBM2 on a 2048-bit bus. The HBM2 implementation provides a much wider physical bus, but the GDDR6 on the PRO V620 runs at a higher effective speed (16 Gbps versus 1704 Mbps), resulting in higher overall bandwidth for the PRO V620.

The MI25's HBM2 memory has a lower clock (852 MHz versus 2000 MHz), which helps explain why the wider bus does not translate into a bandwidth advantage. The PRO V620's memory system is simply more efficient per pin, a benefit of its newer process node and controller design.

The TDP is identical at 300 W for both cards, which is notable given the PRO V620's much higher performance. This means the PRO V620 delivers roughly 65% more FP32 throughput per watt compared to the MI25, assuming both operate at their TDP limits.

Where Each One Wins

Based on the recorded data, the AMD Radeon PRO V620 wins in every measurable category. It has higher OpenCL performance (128,580 versus 68,562), higher FP32 and FP16 compute, more memory, higher bandwidth, faster clocks, more shading units, more TMUs, more ROPs, and includes ray tracing hardware. Its only "loss" is in the physical memory bus width, where the MI25's 2048-bit HBM2 interface exceeds the PRO V620's 256-bit GDDR6 bus, but this does not translate into a performance advantage in the benchmark data.

The PRO V620 is the clear choice for compute-heavy workloads that benefit from raw FP32 or FP16 throughput, large memory buffers, or ray tracing capabilities. Its higher transistor density and newer architecture make it suitable for modern applications that expect DirectX 12 Ultimate or Vulkan 1.4 features.

The MI25's strengths are more limited. Its HBM2 memory, while lower in bandwidth, offers a different access pattern that some specialized workloads might prefer, though this is not reflected in the available benchmarks. Its smaller physical size (111 mm height versus 120 mm) could be an advantage in tight chassis, but both cards are dual-slot and 267 mm long. The MI25 also uses PCIe 3.0, which may be compatible with older server platforms, though this is a compatibility consideration rather than a performance one.

For users with workloads that are memory-bandwidth sensitive and specifically tuned for HBM2, the MI25 might still be functional, but the data does not show any scenario where it outperforms the PRO V620. The 87.5% OpenCL delta is the only direct comparison available, and it is decisive.

The PRO V620's nearest rivals are all modern workstation cards (W6800X Duo, W6800, A10M, RTX 4000 Ada), and it edges each of them by less than 1%. The MI25, by contrast, trails its nearest rivals (Arc A770, CMP 90HX, WX 8200, Quadro P6000) by margins ranging from 0.4% to 2.0%. This places the PRO V620 at the top of its class, while the MI25 sits at the bottom of its own peer group.

In practical terms, the PRO V620 is the only reasonable choice for new deployments based on the recorded performance data. The MI25 remains a legacy part, end-of-life since its 2017 release, and its performance profile is firmly in the past generation.