GPU Comparison

The NVIDIA Quadro K620 and NVIDIA Quadro K4000M are both end-of-life professional workstation graphics cards, but they target fundamentally different use cases. The data shows the K620, a desktop card built on the Maxwell architecture, holds a decisive performance advantage in the single available benchmark, while the K4000M, a mobile Kepler part, offers advantages in memory capacity and interface specifications. This analysis breaks down where each card wins based strictly on the benchmark results and hardware specifications.

The Verdict

The verdict from the data is clear: the NVIDIA Quadro K620 is the faster card. In the head-to-head Geekbench OpenCL test, the K620 scores 6693 versus the K4000M’s 5986, a 11.8% lead. This aligns with their respective average benchmark scores, where the K620 averages 6282 and the K4000M averages 5986. The K620 also holds a higher percentile ranking among all GPUs at 36 compared to the K4000M’s 34.

However, the choice is not solely about raw speed. The K4000M is a mobile module, not a desktop card, so it is only relevant for users upgrading a laptop. For desktop workstation builders, the K620 is the clear pick. For those with a compatible MXM-B (3.0) laptop slot, the K4000M offers 4 GB of memory, double the K620’s 2 GB, which could be a deciding factor for specific large dataset workloads. The K620 wins on performance and efficiency, while the K4000M wins on capacity and form factor suitability.

Where Each One Wins

NVIDIA Quadro K620:

• Compute Performance: The K620 wins the only head-to-head benchmark, Geekbench OpenCL, with 6693 points. Its average benchmark score of 6282 is also higher.
• Clock Speeds: The K620 runs at a base clock of 1058 MHz and boost clock of 1124 MHz, significantly higher than the K4000M’s fixed 601 MHz.
• Efficiency: The K620 has a 45 W TDP, less than half of the K4000M’s 100 W TDP, making it a more power-efficient solution.
• Vulkan Support: The K620 supports Vulkan 1.4, while the K4000M is limited to Vulkan 1.2.175.

NVIDIA Quadro K4000M:

• Memory Capacity: The K4000M has 4 GB of GDDR5 memory, which is double the K620’s 2 GB of DDR3.
• Memory Bandwidth: With a 256-bit bus and 89.60 GB/s bandwidth, the K4000M offers significantly more memory throughput than the K620’s 128-bit bus and 28.80 GB/s.
• Raw Compute Cores: The K4000M has 960 shading units and 80 texture mapping units (TMUs), compared to the K620’s 384 shading units and 24 TMUs. Its FP32 performance of 1,153.9 GFLOPS is also higher than the K620’s 863.2 GFLOPS.
• Form Factor: The K4000M is an MXM Module, designed for portable devices, whereas the K620 is a Single-slot desktop card.

Architecture Differences

The two cards come from different NVIDIA architectures. The K620 is built on the Maxwell architecture using the GM107 chip, while the K4000M uses the older Kepler architecture with the GK104 chip. Both are fabricated on a 28 nm process at TSMC, but the chip designs differ substantially.

The K4000M’s GK104 chip is considerably larger, with 3,540 million transistors on a 294 mm² die. The K620’s GM107 is smaller, with 1,870 million transistors on a 148 mm² die. Despite the K4000M having more transistors, its transistor density is slightly lower at 12.0M / mm² compared to the K620’s 12.6M / mm². This suggests the Maxwell architecture is more efficient in packing transistors.

The memory subsystems are radically different. The K620 uses 2 GB of DDR3 memory on a 128-bit bus, yielding 28.80 GB/s of bandwidth. The K4000M uses 4 GB of GDDR5 memory on a 256-bit bus, yielding 89.60 GB/s of bandwidth, more than three times the K620’s throughput. The K4000M’s memory clock is 700 MHz (or 2.8 Gbps effective), while the K620 runs at 900 MHz (or 1800 Mbps effective).

The K4000M has more execution resources: 960 shading units, 80 TMUs, and 32 ROPs. The K620 has 384 shading units, 24 TMUs, and 16 ROPs. Yet, the K620’s higher clocks (base 1058 MHz vs 601 MHz) give it a higher pixel rate of 17.98 GPixel/s compared to the K4000M’s 12.02 GPixel/s. The K4000M, however, has a higher texture rate of 48.08 GTexel/s versus the K620’s 26.98 GTexel/s.

Both support DirectX 12 (11_0) and OpenGL 4.6. The K620 supports Vulkan 1.4; the K4000M supports Vulkan 1.2.175. The K620 uses a PCIe 2.0 x16 interface, while the K4000M uses an MXM-B (3.0) interface. The K620 has display outputs of 1x DVI and 1x DisplayPort 1.2, while the K4000M's outputs are portable device dependent.

FAQ

Q: Which card is faster in compute benchmarks?

A: The NVIDIA Quadro K620 is faster. In the Geekbench OpenCL test, it scored 6693 against the K4000M’s 5986, an 11.8% difference. The K620’s average benchmark score is 6282 versus 5986 for the K4000M.

Q: Does the K4000M have more memory, and does it matter?

A: Yes, the K4000M has 4 GB of GDDR5 memory, double the K620’s 2 GB of DDR3. It also has a wider 256-bit bus and 89.60 GB/s bandwidth versus 128-bit and 28.80 GB/s. This makes the K4000M better suited for large frame buffers and texture-heavy workloads, despite its lower compute score.

Q: Which card is more power-efficient?

A: The K620 is significantly more power-efficient. It has a 45 W TDP, while the K4000M has a 100 W TDP. The K620 also achieves higher performance with fewer shading units (384 vs 960) and a smaller die (148 mm² vs 294 mm²).

Q: Can the K4000M be used in a desktop PC?

A: No. The K4000M is an MXM Module with an MXM-B (3.0) interface, designed for portable devices. The K620 is a Single-slot desktop card with a PCIe 2.0 x16 interface.

Q: Are they from the same generation of NVIDIA architecture?

A: No. The K620 is based on the newer Maxwell architecture (chip GM107), while the K4000M is based on the older Kepler architecture (chip GK104). Both use a 28 nm process at TSMC.

Q: Which card has better API support?

A: The K620 has better Vulkan support, at version 1.4 versus the K4000M’s 1.2.175. Both cards support DirectX 12 (11_0) and OpenGL 4.6.

Head-to-Head Benchmarks

The only direct benchmark comparison available is the Geekbench OpenCL test, and the results are decisive.

• Geekbench OpenCL: The NVIDIA Quadro K620 scores 6693, while the NVIDIA Quadro K4000M scores 5986. This gives the K620 a 11.8% lead. This result is notable because the K4000M has more than double the shading units (960 vs 384) and significantly higher FP32 compute (1,153.9 GFLOPS vs 863.2 GFLOPS). The K620’s victory is attributable to its much higher clock speeds (1058 MHz base / 1124 MHz boost vs 601 MHz fixed) and its newer Maxwell architecture.

The K620’s performance lead in this test is consistent with its other metrics. It has a higher pixel rate (17.98 GPixel/s vs 12.02 GPixel/s) and a higher average benchmark score (6282 vs 5986). The K4000M, however, counters with a higher texture rate (48.08 GTexel/s vs 26.98 GTexel/s) and superior memory bandwidth (89.60 GB/s vs 28.80 GB/s), but these advantages do not translate into a win in the OpenCL compute benchmark.

The nearest rivals for each card further contextualize the results. The K620’s average score of 6282 places it in close competition with the NVIDIA GeForce RTX 5070 Ti SUPER (6270, +0.2%) and the AMD Radeon Pro WX 4100 (6330, -0.8%). The K4000M’s average of 5986 is virtually tied with the AMD FirePro W4100 (5987, 0.0%) and the NVIDIA Quadro K4000 (5982, +0.1%). This shows that while the K620 is competitive with a much more modern card like the RTX 5070 Ti SUPER, the K4000M is only on par with older or lower-tier workstation parts. In short, the benchmark data shows a clear hierarchy: the K620 outperforms the K4000M in compute, despite the K4000M’s theoretical hardware advantages in core count and memory bandwidth.