NVIDIA Quadro K620M vs NVIDIA RTX A400 Comparison

The NVIDIA RTX A400 and NVIDIA Quadro K620M represent two distant eras of professional mobile graphics. The data shows a stark generational divide, with the RTX A400 delivering a level of compute performance that the older Quadro K620M cannot approach. While both cards target workstation tasks, their architectural foundations and benchmark results place them in entirely different performance classes, making the choice between them dependent on the specific demands of the workload.

Where Each One Wins

The benchmark results are unequivocal in favor of the RTX A400. In the sole head-to-head benchmark available, Geekbench OpenCL, the RTX A400 decisively outperforms the Quadro K620M. The RTX A400 scores 22,844 points, a massive 283.5% improvement over the Quadro K620M's 5,957 points. This indicates that for any general-purpose GPU compute task, the RTX A400 is the clear winner, offering over three times the processing power.

The Quadro K620M, however, holds a distinct advantage in one specific area: power consumption. Its thermal design power (TDP) is rated at just 30 W, compared to the RTX A400's 50 W. This lower power draw suggests the Quadro K620M could be better suited for legacy mobile workstations where thermal headroom and battery life are critical, even at the cost of significant performance. For applications that are not compute-intensive, the Quadro K620M's efficiency could be a deciding factor in preserving system longevity.

In terms of overall performance percentile, the two cards are surprisingly close. The RTX A400 sits in the 35th percentile of all GPUs, while the Quadro K620M is just one point behind at the 34th percentile. This near-parity in percentile ranking confirms the vast range of GPUs in the database, and it contextualizes the head-to-head results: while the RTX A400 is dramatically faster, both cards are positioned in the lower half of the performance spectrum. The RTX A400's average benchmark score of 6,078 places it nearly at parity with its nearest rival, the NVIDIA GeForce MX230, which scores 6,077. The Quadro K620M's average score of 5,957 is similarly close to its own nearest rival, the AMD Radeon HD 8730M, at 5,955.

Architecture Differences

The two GPUs are built on fundamentally different architectures, representing a major technological leap. The RTX A400 is based on the Ampere architecture, using the GA107 chip, while the Quadro K620M uses the much older Maxwell architecture with the GM108S chip. This architectural difference is reflected in the manufacturing process: the RTX A400 is built on an 8 nm process at Samsung, whereas the Quadro K620M uses a 28 nm process at TSMC.

This process shrink allows for a staggering difference in transistor count and density. The RTX A400 packs 8,700 million transistors onto a 200 mm² die, achieving a density of 43.5 million transistors per square millimeter. In contrast, the Quadro K620M has only 1,020 million transistors on a 77 mm² die, with a density of 13.2 million transistors per square millimeter. This means the RTX A400 has over eight times the transistors in roughly 2.5 times the die area, enabling its far greater compute capabilities.

The core configurations are equally divergent. The RTX A400 features 768 shading units, 24 texture mapping units (TMUs), and 16 render output units (ROPs). It also includes specialized hardware in the form of 6 ray tracing cores and 24 tensor cores, which are entirely absent from the Quadro K620M. The Quadro K620M, by contrast, has only 384 shading units, 16 TMUs, and 8 ROPs. Clock speeds also differ, with the RTX A400 having a base clock of 1417 MHz and a boost clock of 1762 MHz, compared to the Quadro K620M's 1029 MHz base and 1124 MHz boost clocks.

The memory subsystems highlight the performance gap further. The RTX A400 uses 4 GB of GDDR6 memory on a 64-bit bus, delivering a bandwidth of 96.00 GB/s. The Quadro K620M uses 2 GB of DDR3 memory, also on a 64-bit bus, but its bandwidth is severely limited at just 16.02 GB/s. The RTX A400's memory is six times faster, which is crucial for data-intensive workloads. The RTX A400 also supports modern API features, including DirectX 12 Ultimate (12_2), while the Quadro K620M is limited to DirectX 12 (11_0). Both support OpenGL 4.6 and Vulkan 1.4.

Head-to-Head Benchmarks

The single available head-to-head benchmark, Geekbench OpenCL, provides a clear and dramatic picture of the performance difference. The RTX A400 achieves a score of 22,844, while the Quadro K620M manages only 5,957. This results in a delta of 283.5%, meaning the RTX A400 is nearly four times faster in this compute test. This is not a marginal improvement; it is a generational leap in raw processing power.

This level of performance disparity is characteristic of the architectural advancements between the two cards. The RTX A400's FP32 compute rating is 2.706 TFLOPS, while the Quadro K620M is rated at just 863.2 GFLOPS. This means the RTX A400 can perform over three times as many floating-point operations per second. Similarly, the pixel rate of the RTX A400 is 28.19 GPixel/s versus 8.992 GPixel/s for the Quadro K620M, and the texture rate is 42.29 GTexel/s versus 17.98 GTexel/s. Every measurable aspect of throughput is significantly higher on the RTX A400.

The RTX A400 also benefits from a much faster memory clock, with a 1500 MHz base and 12 Gbps effective rate, compared to the Quadro K620M's 1001 MHz base and 2 Gbps effective rate. While the memory bus width is identical at 64-bit, the faster memory type and clock speed translate directly into the six-fold bandwidth advantage. The RTX A400's support for FP16 compute at a 1:1 ratio with FP32, a feature the Quadro K620M lacks, further extends its utility in modern AI and machine learning workloads that leverage mixed-precision calculations.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The NVIDIA RTX A400 has a higher average benchmark score of 6,078, compared to the NVIDIA Quadro K620M's average score of 5,957. This places the RTX A400 slightly ahead in overall performance metrics.

Q: Is the RTX A400 more power-efficient than the Quadro K620M?

A: No. The Quadro K620M has a significantly lower thermal design power (TDP) of 30 W, while the RTX A400 is rated at 50 W. For a given performance target, the Quadro K620M draws less power, but it delivers far less performance.

Q: What are the key differences in memory technology?

A: The RTX A400 uses 4 GB of GDDR6 memory, while the Quadro K620M uses 2 GB of DDR3 memory. Both have a 64-bit bus, but the RTX A400's memory bandwidth is 96.00 GB/s, which is six times higher than the Quadro K620M's 16.02 GB/s.

Q: Does the RTX A400 have any specialized compute cores?

A: Yes, the RTX A400 includes 6 ray tracing cores and 24 tensor cores, which are designed for ray-traced rendering and AI acceleration. The Quadro K620M has no such dedicated hardware, as it is based on the older Maxwell architecture.

Q: How do their production statuses compare?

A: The NVIDIA RTX A400 is listed as "Active" in production, while the NVIDIA Quadro K620M is marked as "End-of-life." This indicates that the RTX A400 is a current product, whereas the Quadro K620M is a legacy component.

Q: What is the performance difference in the Geekbench OpenCL test?

A: The RTX A400 scores 22,844, which is 283.5% higher than the Quadro K620M's score of 5,957. This represents a nearly four-fold performance advantage for the RTX A400 in this compute benchmark.

Specification Differences

The specification sheets for the two GPUs reveal fundamental differences across nearly every category. The process node is a major differentiator: the RTX A400 is fabricated on an 8 nm process, while the Quadro K620M uses a 28 nm process. The transistor count is also vastly different, with the RTX A400 containing 8,700 million transistors compared to the Quadro K620M's 1,020 million. The die size is 200 mm² for the RTX A400 and 77 mm² for the Quadro K620M.

Clock speeds are higher on the RTX A400, which has a base clock of 1417 MHz and a boost clock of 1762 MHz. The Quadro K620M has a base clock of 1029 MHz and a boost clock of 1124 MHz. Memory configurations are also distinct: the RTX A400 has 4 GB of GDDR6 with a bandwidth of 96.00 GB/s, while the Quadro K620M has 2 GB of DDR3 with a bandwidth of 16.02 GB/s. The memory clock is 1500 MHz (12 Gbps effective) for the RTX A400 and 1001 MHz (2 Gbps effective) for the Quadro K620M.

The core architectures differ significantly. The RTX A400 has 768 shading units, 24 TMUs, and 16 ROPs, along with 6 RT cores and 24 tensor cores. The Quadro K620M has 384 shading units, 16 TMUs, and 8 ROPs, with no RT or tensor cores. The pixel rate is 28.19 GPixel/s for the RTX A400 versus 8.992 GPixel/s for the Quadro K620M. Texture rates are 42.29 GTexel/s and 17.98 GTexel/s, respectively. FP32 compute is 2.706 TFLOPS for the RTX A400, while the Quadro K620M is rated at 863.2 GFLOPS. The RTX A400 also supports FP16 compute at 2.706 TFLOPS, a feature absent from the Quadro K620M.

The TDP is 50 W for the RTX A400 and 30 W for the Quadro K620M. The slot width is single-slot for the RTX A400, whereas the Quadro K620M is an MXM Module. The bus interface is PCIe 4.0 x8 for the RTX A400, while the Quadro K620M uses MXM-A (3.0). Display outputs are 4x mini-DisplayPort 1.4a for the RTX A400, while the Quadro K620M's outputs are listed as "Portable Device Dependent." The RTX A400 supports DirectX 12 Ultimate (12_2), while the Quadro K620M is limited to DirectX 12 (11_0). The release dates are also far apart, with the RTX A400 released on 2024-04-15 and the Quadro K620M on 2015-02-28.