NVIDIA Quadro K620 vs NVIDIA Quadro K620M Comparison

The NVIDIA Quadro K620 and NVIDIA Quadro K620M are both end-of-life professional mobile/desktop graphics solutions built on the same Maxwell architecture and 28 nm TSMC process. Despite sharing a nearly identical name and identical FP32 compute throughput, the data shows they are distinctly different performers, with the desktop-oriented K620 holding a clear advantage in the one benchmark where they directly compete.

Head-to-Head Benchmarks

The only direct comparison available is the Geekbench OpenCL test, and the results are decisive. The NVIDIA Quadro K620 scores 6693 points, while the NVIDIA Quadro K620M trails with 5957 points. This represents a 12.4% delta in favor of the K620, a substantial margin that underscores fundamental differences in their hardware configuration.

The source of this performance gap is not compute power. Both cards deliver exactly 863.2 GFLOPS of FP32 performance, meaning their raw shading capability is identical. Instead, the K620’s advantage comes from its memory subsystem. The K620 uses a 128-bit memory bus, while the K620M is limited to a 64-bit bus. Consequently, the K620 achieves a memory bandwidth of 28.80 GB/s, whereas the K620M manages only 16.02 GB/s — a 79.8% advantage for the desktop card. This bandwidth disparity directly impacts OpenCL workloads, which often rely heavily on data movement rather than pure arithmetic.

The pixel and texture processing rates further illustrate the gap. The K620 outputs 17.98 GPixel/s and 26.98 GTexel/s, while the K620M is halved in pixel throughput at 8.992 GPixel/s and sees its texture rate drop to 17.98 GTexel/s. These figures are a direct consequence of the K620 having 16 ROPs and 24 TMUs, versus the K620M’s 8 ROPs and 16 TMUs. For fill-rate-limited tasks, the K620 is effectively twice as fast.

It is also worth noting the competitive context. The K620’s average benchmark score of 6282 places it near the NVIDIA GeForce RTX 5070 Ti SUPER (6270, 0.2% delta) and the AMD Radeon Pro WX 4100 (6330, -0.8% delta). The K620M’s average of 5957 puts it in a much lower tier, alongside the AMD Radeon HD 8730M (5955, 0% delta) and the integrated Intel UHD Graphics 730 (5929, 0.5% delta). This positioning shows that while the K620 competes with modern discrete GPUs in this specific synthetic test, the K620M is closer in performance to entry-level integrated graphics.

Where Each One Wins

The NVIDIA Quadro K620 wins in every measurable category. It has the higher OpenCL score, the wider memory bus, the greater bandwidth, the higher pixel and texture fill rates, and more TMUs and ROPs. For any workload that stresses memory throughput or fill-rate — such as large texture loads, high-resolution compositing, or multi-sample anti-aliasing — the K620 is the clear choice.

The NVIDIA Quadro K620M does have one significant advantage: power consumption. The K620M is rated at 30 W TDP, while the K620 draws 45 W. This 15 W difference makes the K620M a more suitable option for thermally constrained environments. Additionally, the K620M uses an MXM-A (3.0) form factor, which is designed for portable workstations, whereas the K620 is a single-slot, 160 mm (6.3 inches) long card that requires a PCIe 2.0 x16 slot. The K620M also has a higher transistor density (13.2M / mm²) on a smaller die (77 mm²) compared to the K620’s 12.6M / mm² on a 148 mm² die, indicating a more compact implementation.

The K620M’s memory clock is higher at 1001 MHz (2 Gbps effective) versus the K620’s 900 MHz (1800 Mbps effective), but this cannot compensate for the 64-bit bus disadvantage. In the single benchmark available, the K620M wins zero categories. Its only theoretical wins are in portability and power efficiency, not in raw performance.

The Verdict

The data is unambiguous. The NVIDIA Quadro K620 is the superior performer, winning the only head-to-head benchmark by 12.4%. Its memory bandwidth advantage of 28.80 GB/s versus 16.02 GB/s is the primary differentiator, and its fill rates are exactly double in pixel throughput. For any professional application that relies on OpenCL compute, the K620 delivers a significant uplift.

The NVIDIA Quadro K620M is not without merit, but its merits are not performance-related. At 30 W, it consumes one-third less power than the K620’s 45 W, and its MXM module form factor makes it the only choice for laptops and compact mobile workstations. If the system requires a low-power, portable professional GPU, the K620M is the functional option. However, its average benchmark score of 5957 places it in the 34th percentile of all GPUs, just below the K620’s 36th percentile.

Users should select the K620 if they have a desktop chassis with a PCIe slot and prioritize compute throughput, memory bandwidth, or fill-rate performance. The K620M should only be chosen when the MXM-A form factor is mandatory, as its performance is strictly lower across the board. The K620’s closest rivals in the database — the GeForce RTX 5070 Ti SUPER and the Radeon Pro WX 4100 — have nearly identical average scores, confirming that the K620 punches above its class in synthetic compute. The K620M, conversely, sits alongside integrated graphics, indicating it is best reserved for basic professional visualization rather than demanding compute tasks.

FAQ

Q: Which GPU has a higher Geekbench OpenCL score?

A: The NVIDIA Quadro K620 scores 6693, while the NVIDIA Quadro K620M scores 5957. This gives the K620 a 12.4% advantage in the head-to-head benchmark.

Q: Are the two cards equally powerful in raw compute?

A: Yes, both the NVIDIA Quadro K620 and the NVIDIA Quadro K620M deliver exactly 863.2 GFLOPS of FP32 performance. Their shading units are identical at 384.

Q: Why does the K620 perform better if the FP32 output is the same?

A: The K620 has a 128-bit memory bus with 28.80 GB/s bandwidth, compared to the K620M’s 64-bit bus with 16.02 GB/s. Additionally, the K620 has 24 TMUs and 16 ROPs, versus the K620M’s 16 TMUs and 8 ROPs, leading to higher fill rates.

Q: What is the power consumption difference?

A: The NVIDIA Quadro K620 has a TDP of 45 W, while the NVIDIA Quadro K620M has a lower TDP of 30 W. This makes the K620M more energy-efficient for portable applications.

Q: Are these cards compatible with the same systems?

A: No. The K620 uses a PCIe 2.0 x16 interface and is a 160 mm single-slot card. The K620M uses an MXM-A (3.0) interface, which is designed for modular mobile workstations.

Q: How do these cards compare to their nearest rivals in the database?

A: The K620’s average score of 6282 is 0.2% above the NVIDIA GeForce RTX 5070 Ti SUPER (6270) and 0.8% below the AMD Radeon Pro WX 4100 (6330). The K620M’s average of 5957 is 0% from the AMD Radeon HD 8730M (5955) and 0.5% above the Intel UHD Graphics 730 (5929).

Architecture Differences

The NVIDIA Quadro K620 and K620M share the same Maxwell architecture and are both fabricated by TSMC on a 28 nm process. However, they use different chips. The K620 is based on the GM107 chip, while the K620M uses the smaller GM108S chip. This leads to a significant difference in transistor count: the GM107 contains 1,870 million transistors on a 148 mm² die, resulting in a transistor density of 12.6M / mm². The GM108S is much smaller, with 1,020 million transistors on a 77 mm² die, giving it a higher density of 13.2M / mm².

Memory architecture is the most consequential difference. The K620 features 2 GB of DDR3 memory on a 128-bit bus, achieving 28.80 GB/s of bandwidth. The K620M also has 2 GB of DDR3, but on a 64-bit bus, halving bandwidth to 16.02 GB/s. While the K620M runs its memory at a higher effective speed (2 Gbps vs. 1800 Mbps), the narrower bus negates this advantage.

The compute core configurations are identical in shading units (384) but differ in ancillary hardware. The K620 has 24 TMUs and 16 ROPs, while the K620M has 16 TMUs and 8 ROPs. This results in the K620 achieving 26.98 GTexel/s and 17.98 GPixel/s, versus the K620M’s 17.98 GTexel/s and 8.992 GPixel/s.

Clock speeds are nearly identical. The K620 has a base clock of 1058 MHz and a boost of 1124 MHz. The K620M has a base of 1029 MHz and the same 1124 MHz boost. Both cards support DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.4. Display outputs differ: the K620 offers 1x DVI and 1x DisplayPort 1.2, while the K620M’s outputs are listed as “Portable Device Dependent,” reflecting its mobile nature. The K620 is a single-slot card requiring a 200 W suggested PSU, whereas the K620M is an MXM module with no suggested PSU listed. Neither card requires external power connectors, and both lack ray tracing and tensor cores.