AMD Radeon Pro Vega 20 vs NVIDIA RTX A4000 Comparison

The AMD Radeon Pro Vega 20 and NVIDIA RTX A4000 are both end-of-life workstation graphics solutions, but the benchmark data reveals a decisive generational and architectural gap. The RTX A4000 is the clear performance leader, winning both head-to-head benchmark comparisons by a massive margin, while the Radeon Pro Vega 20’s only advantage lies in its integrated form factor and lower power draw. The data shows the NVIDIA card delivers roughly four times the raw compute throughput in OpenCL and nearly five times in Vulkan, making it the only choice for demanding GPU-accelerated workflows, provided the system can accommodate a discrete card.

Where Each One Wins

The benchmark results are unequivocal: the NVIDIA RTX A4000 wins every single comparative test. In the Geekbench OpenCL test, the RTX A4000 scores 105,739 against the Radeon Pro Vega 20’s 26,679, a delta of -74.8% from the AMD card’s perspective. The Vulkan test is even more lopsided, with the RTX A4000 posting 127,645 versus 26,410, a -79.3% delta. The RTX A4000’s dominance is not marginal; it is a categorical shift in compute capability.

The AMD Radeon Pro Vega 20’s "wins" are not in raw performance but in its physical and power characteristics. It is an IGP (integrated graphics processor) with a 100 W TDP, whereas the RTX A4000 is a single-slot, 140 W discrete card requiring a 6-pin power connector and a 300 W suggested PSU. The AMD card also uses a PCIe 3.0 x16 interface, while the RTX A4000 uses PCIe 4.0 x16. For a portable or space-constrained system, the Vega 20 is the only option that can be embedded directly onto a motherboard, eliminating the need for expansion slot clearance. However, this is a niche advantage that cannot compensate for the performance deficit.

In terms of overall standing, the Radeon Pro Vega 20 holds a 73rd percentile ranking among all GPUs, with an average benchmark score of 27,839. The RTX A4000 sits at the 72nd percentile with an average score of 26,683. This means the AMD part actually has a slightly higher percentile ranking, but this is misleading. The RTX A4000’s average is dragged down by its Passmark scores, which include older DirectX 9 and 10 tests where it scores very low (240 and 126, respectively). The Vega 20’s benchmark suite only includes Geekbench tests, which skew the comparison. The data shows that the NVIDIA card’s average is not representative of its peak capabilities, while the AMD card’s is.

FAQ

Q: Which GPU is faster in raw compute performance?

A: The NVIDIA RTX A4000 is overwhelmingly faster. In the Geekbench OpenCL test, it scores 105,739 versus 26,679 for the AMD Radeon Pro Vega 20, a 74.8% advantage. In the Vulkan test, the margin is 79.3% in favor of the RTX A4000 (127,645 vs 26,410).

Q: Does the AMD Radeon Pro Vega 20 have any performance advantage?

A: No. The head-to-head data shows zero benchmark wins for the AMD card. Its only advantages are physical: it is an IGP with a 100 W TDP, while the RTX A4000 is a 140 W discrete card. It also has a higher GPU percentile ranking (73rd vs 72nd), but this is an artifact of the different benchmark suites used.

Q: What are the memory specifications for each card?

A: The AMD Radeon Pro Vega 20 has 4 GB of HBM2 memory on a 1024-bit bus, providing 189.4 GB/s of bandwidth. The NVIDIA RTX A4000 has 16 GB of GDDR6 memory on a 256-bit bus, providing 448.0 GB/s of bandwidth.

Q: Which card supports hardware ray tracing?

A: Only the NVIDIA RTX A4000. It features 48 dedicated RT cores and 192 tensor cores, while the AMD Radeon Pro Vega 20 has no RT or tensor cores. The RTX A4000 also supports DirectX 12 Ultimate (12_2), while the AMD card supports DirectX 12 (12_1).

Q: Are these cards still in production?

A: No. Both are marked as end-of-life. The AMD Radeon Pro Vega 20 was released on November 13, 2018, and the NVIDIA RTX A4000 was released on April 11, 2021.

Q: How do these cards compare to their closest rivals?

A: The AMD Radeon Pro Vega 20’s nearest rival is the AMD Radeon RX 7800M, which scores 27,883, a mere 0.2% difference. The RTX A4000’s nearest rival is the AMD Radeon RX 5700 XT 50th Anniversary, which scores 26,553, a 0.5% difference. Both cards are closely matched to their respective rivals.

Architecture Differences

The architectural gap between these two cards is vast. The AMD Radeon Pro Vega 20 is built on the Vega 12 chip using the GCN 5.0 architecture on a 14 nm process from GlobalFoundries. It has 1280 shading units, 80 TMUs, and 32 ROPs. Its compute capabilities are rated at 3.284 TFLOPS for FP32 and 6.569 TFLOPS for FP16 (2:1 ratio). The NVIDIA RTX A4000 is built on the GA104 chip using the Ampere architecture on an 8 nm process from Samsung. It has 6,144 shading units, 192 TMUs, and 96 ROPs. Its FP32 and FP16 performance are both 19.17 TFLOPS (1:1 ratio).

The RTX A4000 also includes hardware features absent from the AMD card: 48 RT cores for ray tracing and 192 tensor cores for AI acceleration. The AMD card has no such dedicated units. The RTX A4000’s transistor count is 17,400 million on a 392 mm² die, with a density of 44.4M / mm². The Vega 20’s transistor count and die size are not listed in the data, but the 14 nm process node indicates a significantly older and less dense design. The RTX A4000 supports a newer API set, including DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the AMD card only supports DirectX 12 (12_1) and Vulkan 1.3. Both support OpenGL 4.6.

The memory architecture is also fundamentally different. The AMD card uses 4 GB of HBM2 on a 1024-bit bus, which is a wide but low-capacity configuration. The NVIDIA card uses 16 GB of GDDR6 on a 256-bit bus, which is narrower but offers higher capacity and greater bandwidth (448.0 GB/s vs 189.4 GB/s). The process node difference (14 nm vs 8 nm) and the presence of specialized cores on the NVIDIA part explain the massive performance gap.

Head-to-Head Benchmarks

The head-to-head data is limited to two tests, but both are decisive. In the Geekbench OpenCL test, the NVIDIA RTX A4000 scores 105,739, which is 79,060 points higher than the AMD Radeon Pro Vega 20’s 26,679. The delta of -74.8% indicates that the AMD card performs at roughly a quarter of the NVIDIA card’s level. This is a direct reflection of the shading unit count (6,144 vs 1,280) and the FP32 throughput (19.17 TFLOPS vs 3.284 TFLOPS).

The Geekbench Vulkan test shows a similar pattern. The RTX A4000 scores 127,645, while the Vega 20 scores 26,410, a delta of -79.3%. The Vulkan test is even more favorable to the NVIDIA card, likely due to its newer architecture and driver optimizations. The RTX A4000’s Vulkan score is 21,906 points higher than its OpenCL score, while the AMD card’s Vulkan score is actually 269 points lower than its OpenCL score. This suggests the NVIDIA architecture is better optimized for modern, low-level graphics APIs.

The RTX A4000 also has additional benchmark data not available for the AMD card. In Passmark, it scores 19,459 in G3D, 9,760 in GPU Compute, and 1,024 in G2D. Its DirectX 9 score is 240, DirectX 10 is 126, DirectX 11 is 158, and DirectX 12 is 72. These scores show that the RTX A4000 is a capable compute card but has relatively weak legacy DirectX performance. The 3DMark Steel Nomad DX12 score of 2,604 further confirms its modern API strength. None of these tests are available for the AMD card, so a direct comparison is impossible, but the Geekbench results alone are sufficient to establish the RTX A4000’s dominance.

Specification Differences

The two cards differ in almost every measurable specification. The AMD Radeon Pro Vega 20 uses a 14 nm process from GlobalFoundries, while the NVIDIA RTX A4000 uses an 8 nm process from Samsung. The NVIDIA card has 17,400 million transistors on a 392 mm² die, whereas the AMD card’s transistor count and die size are not listed. Clock speeds differ: the AMD card has a base clock of 815 MHz and a boost of 1283 MHz, while the NVIDIA card has a lower base clock of 735 MHz but a significantly higher boost clock of 1560 MHz.

Memory is a major differentiator. The AMD card has 4 GB of HBM2 on a 1024-bit bus with 189.4 GB/s bandwidth. The NVIDIA card has 16 GB of GDDR6 on a 256-bit bus with 448.0 GB/s bandwidth. The compute units are also vastly different: 1280 shading units, 80 TMUs, and 32 ROPs for AMD versus 6,144 shading units, 192 TMUs, and 96 ROPs for NVIDIA. The pixel rate is 41.06 GPixel/s for AMD versus 149.8 GPixel/s for NVIDIA. The texture rate is 102.6 GTexel/s versus 299.5 GTexel/s.

Power and physical characteristics differ as well. The AMD card has a 100 W TDP and is an IGP, while the NVIDIA card has a 140 W TDP, is single-slot, and requires a 6-pin power connector and a 300 W suggested PSU. The NVIDIA card is 241 mm long and 112 mm high. The AMD card has no listed dimensions. The bus interface is PCIe 3.0 x16 for AMD and PCIe 4.0 x16 for NVIDIA. Display outputs are "Portable Device Dependent" for AMD and 4x DisplayPort 1.4a for NVIDIA. The AMD card has no RT or tensor cores, while the NVIDIA card has 48 and 192, respectively.

The Verdict

The verdict is clear from the data: the NVIDIA RTX A4000 is the superior workstation GPU for any task that requires raw compute performance. It is 74.8% faster in OpenCL and 79.3% faster in Vulkan than the AMD Radeon Pro Vega 20. It offers four times the memory capacity (16 GB vs 4 GB) and more than double the memory bandwidth (448.0 GB/s vs 189.4 GB/s). Its FP32 throughput is 19.17 TFLOPS versus 3.284 TFLOPS, and it includes RT and tensor cores for ray tracing and AI workloads. The RTX A4000 is the only viable choice for professionals running 3D rendering, machine learning, or other compute-heavy applications.

However, the RTX A4000 is not universally applicable. It is a discrete card that requires a PCIe 4.0 slot, a 6-pin power connector, and a 300 W PSU. The AMD Radeon Pro Vega 20, as an IGP with a 100 W TDP, can be integrated into a portable or compact system where adding a discrete card is impossible. For users with such constraints, the Vega 20 is the only option, despite its severe performance limitations. The data also shows that the AMD card has a slightly higher percentile ranking (73rd vs 72nd), but this is misleading given the different benchmark suites. Ultimately, the RTX A4000 is the performance winner, while the Vega 20 wins only on integration and power draw.