AMD Radeon RX 6650 XT vs NVIDIA RTX A4000 Mobile Comparison

# NVIDIA RTX A4000 Mobile vs AMD Radeon RX 6650 XT

The NVIDIA RTX A4000 Mobile and AMD Radeon RX 6650 XT represent two fundamentally different approaches to GPU design: a mobile workstation part built on Ampere architecture versus a desktop gaming card based on RDNA 2.0. Benchmark results show a clear split — AMD wins seven of the nine head-to-head tests, but NVIDIA's single OpenCL victory is so dominant that it reshapes the overall narrative. The RTX A4000 Mobile averages 21,379 across all benchmarks versus 19,765 for the RX 6650 XT, placing both in the mid-60s percentile of all GPUs (66th for NVIDIA, 65th for AMD).

Head-to-Head Benchmarks

The biggest headline is the Geekbench OpenCL result, where the RTX A4000 Mobile scores 97,178 against the RX 6650 XT's 10,111. That is a staggering 861.1% advantage for NVIDIA, a delta so large it suggests fundamental differences in how each card handles compute workloads under this particular test. The A4000 Mobile's FP32 throughput of 17.20 TFLOPS versus 10.79 TFLOPS for the AMD card partially explains the gap, but the magnitude still dwarfs what raw specs would predict.

Outside that outlier, the RX 6650 XT controls nearly every other benchmark. In Geekbench Vulkan, AMD leads 81,306 to 73,002, a 10.2% margin — a notable reversal from the OpenCL result, indicating AMD's architecture handles Vulkan's compute paths more efficiently. The PassMark DirectX suite further tilts toward AMD: DirectX 11 shows 169 versus 127 (24.9% ahead), DirectX 9 shows 215 versus 157 (27% ahead), and DirectX 10 shows 109 versus 105 (3.7% ahead). The one DirectX exception is DirectX 12, where NVIDIA edges ahead 66 to 62, a 6.5% win.

The remaining PassMark tests all favor AMD. The 3D graphics score goes to the RX 6650 XT at 17,166 versus 14,796, a 13.8% gap. GPU compute shows 7,532 versus 6,394, a 15.1% margin. The 2D graphics test is the most lopsided non-OpenCL result: 918 versus 585, giving AMD a 36.3% advantage. In total, NVIDIA claims two wins (OpenCL and DirectX 12), while AMD takes seven.

Where Each One Wins

The RTX A4000 Mobile is the clear choice for OpenCL-centric workloads. Its 97178 OpenCL score is nearly ten times the RX 6650 XT's, making it the dominant part for any application that leverages OpenCL compute — think scientific simulation, engineering analysis, or medical imaging pipelines. The card's 40 RT cores and 160 tensor cores provide hardware acceleration for ray tracing and AI inference that the AMD card lacks on the tensor side (the RX 6650 XT has zero tensor cores). For professionals running CUDA-adjacent or OpenCL-heavy stacks, the A4000 Mobile's 17.20 TFLOPS FP32 and 17.20 TFLOPS FP16 (1:1 ratio) provide a compute foundation the AMD part cannot match.

The RX 6650 XT wins on virtually every gaming and general-purpose front. Its DirectX 9, 10, and 11 scores are all higher, with the DirectX 9 gap (27%) and DirectX 11 gap (24.9%) being particularly meaningful for legacy game compatibility. The 13.8% lead in PassMark G3D directly translates to better rasterization performance in modern titles. The 36.3% advantage in G2D indicates snappier 2D interface rendering, useful for desktop compositing and productivity apps. Its 21.59 TFLOPS FP16 (2:1 ratio) outpaces NVIDIA's 17.20 TFLOPS, making it stronger for workloads that can exploit half-precision math. The 168.6 GPixel/s pixel rate and 337.3 GTexel/s texture rate both exceed NVIDIA's 134.4 GPixel/s and 268.8 GTexel/s, giving AMD the edge in fill-rate-bound scenarios.

Architecture Differences

The two GPUs come from different foundries and process nodes. NVIDIA uses Samsung's 8 nm process for the GA104 chip, packing 17,400 million transistors into a 392 mm² die (44.4M transistors per mm²). AMD relies on TSMC's 7 nm node for Navi 23, fitting 11,060 million transistors into a smaller 237 mm² die, achieving a higher density of 46.7M transistors per mm².

Core configurations diverge sharply. The RTX A4000 Mobile fields 5,120 shading units, 160 TMUs, and 80 ROPs, along with 40 RT cores and 160 tensor cores. The RX 6650 XT has 2,048 shading units, 128 TMUs, and 64 ROPs, with 32 RT cores but no tensor cores. Despite having fewer than half the shading units, AMD achieves competitive rasterization through higher clocks: base 2055 MHz and boost 2635 MHz, versus NVIDIA's 1140 MHz base and 1680 MHz boost.

Memory subsystems differ in bus width and bandwidth. NVIDIA uses a 256-bit bus with 8 GB GDDR6 at 384.0 GB/s, while AMD uses a 128-bit bus with 8 GB GDDR6 at 280.3 GB/s. The A4000 Mobile's wider bus gives it 37% more bandwidth, which helps in compute-heavy tasks. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The A4000 Mobile connects via PCIe 4.0 x16, while the RX 6650 XT uses PCIe 4.0 x8.

Power and physical design tell different stories. The A4000 Mobile is a 115 W part with no power connectors, designed for portable devices. The RX 6650 XT draws 176 W, requires a single 8-pin connector, a 450 W suggested PSU, and occupies a dual-slot form factor. It also offers fixed display outputs (1x HDMI 2.1, 3x DisplayPort 1.4a), whereas the NVIDIA card's outputs are portable-device dependent.

FAQ

Q: Why does the RTX A4000 Mobile have such a massive OpenCL lead?

A: The A4000 Mobile scores 97,178 in Geekbench OpenCL versus 10,111 for the RX 6650 XT, an 861.1% difference. This likely stems from NVIDIA's 5,120 shading units and 17.20 TFLOPS FP32 throughput, combined with driver optimizations for OpenCL compute paths.

Q: Which card is better for DirectX 12 gaming?

A: The RTX A4000 Mobile wins the PassMark DirectX 12 test 66 to 62, a 6.5% margin. However, the RX 6650 XT leads in DirectX 9, 10, and 11, with the largest gap being 27% in DirectX 9.

Q: Does the RX 6650 XT outperform in Vulkan?

A: Yes. The AMD card scores 81,306 in Geekbench Vulkan versus 73,002 for NVIDIA, a 10.2% advantage. This suggests AMD's RDNA 2.0 architecture handles Vulkan's asynchronous compute features more effectively.

Q: What are the transistor and die size differences?

A: NVIDIA's GA104 has 17,400 million transistors on a 392 mm² die using Samsung 8 nm. AMD's Navi 23 has 11,060 million transistors on a 237 mm² die using TSMC 7 nm. AMD achieves higher density at 46.7M transistors/mm² versus 44.4M for NVIDIA.

Q: Which card has better memory bandwidth?

A: The RTX A4000 Mobile provides 384.0 GB/s over a 256-bit bus, while the RX 6650 XT delivers 280.3 GB/s over a 128-bit bus. NVIDIA's bandwidth advantage is 37%, which benefits compute and high-resolution texture streaming.

Q: Are both cards still in production?

A: No. Both are marked end-of-life. The RTX A4000 Mobile was released in April 2021, and the RX 6650 XT followed in May 2022.

The Verdict

The data presents a clear bifurcation. For OpenCL-centric professional workloads, the RTX A4000 Mobile is the only rational choice — its 97178 OpenCL score is unmatched, and its 40 RT cores and 160 tensor cores provide hardware features the RX 6650 XT simply does not have. The 115 W power envelope and no-connector design also make it suitable for mobile workstations where power is constrained.

For general gaming, rasterization, and legacy DirectX titles, the RX 6650 XT is superior. It wins 7 of 9 benchmarks, holds a 13.8% lead in PassMark G3D, a 36.3% lead in G2D, and a 15.1% lead in GPU compute. Its higher boost clock (2635 MHz vs 1680 MHz) and fill rates (168.6 GPixel/s vs 134.4 GPixel/s) translate directly into better frame rates across most gaming scenarios.

The overall average benchmark score favors NVIDIA (21,379 vs 19,765), but that margin is entirely driven by the OpenCL outlier. Excluding that test, AMD leads nearly everywhere. The verdict depends on workload: choose the RTX A4000 Mobile for compute-heavy OpenCL professional tasks; choose the RX 6650 XT for gaming, DirectX legacy titles, and general-purpose rasterization. Both cards sit at the 65th–66th percentile of all GPUs, meaning neither is a top-tier performer — but each excels in its intended domain.