NVIDIA Quadro K4000 vs NVIDIA Quadro K620 Comparison

The NVIDIA Quadro K620 and NVIDIA Quadro K4000 are both end-of-life professional workstation cards from NVIDIA, but they represent different architectural generations and performance tiers. The data in the FACT PACK reveals a clear performance hierarchy between the two, with the K4000 taking the lead in every head-to-head benchmark, despite the K620 being a newer design. This analysis will dissect the benchmark results, architectural differences, and specification gaps to determine which card is suited for which professional workload.

Head-to-Head Benchmarks

The head-to-head benchmark data is unequivocal, showing the NVIDIA Quadro K4000 winning both available tests. In the Geekbench OpenCL test, the K4000 scores 6816 against the K620’s 6693, a delta of -1.8% for the K620. While this is a narrow margin, it is still a definitive win for the K4000, indicating a slight edge in general compute workloads that leverage OpenCL. The difference is more pronounced in the Geekbench Vulkan test, where the K4000 scores 6964 compared to the K620’s 5870. This represents a substantial 15.7% lead for the K4000, suggesting a significant advantage in APIs that utilize modern graphics and compute pipelines more heavily.

These results are interesting because they invert the expected narrative based on release dates. The K620, with its newer Maxwell architecture, is not able to overcome the raw hardware advantages of the older, larger Kepler-based K4000. The win count is a clean sweep for the K4000, with 2 wins and 0 for the K620. The average benchmark score further corroborates this, with the K4000 averaging 5982 points across its available benchmarks (including a Geekbench Metal score of 4166) versus the K620’s 6282 average across its two benchmarks. While the K620’s average is higher, this is skewed by the fact that it lacks the lower Metal score that drags down the K4000’s average. When comparing the shared benchmarks, the K4000 is the clear victor.

The Verdict

From the data, the NVIDIA Quadro K4000 is the superior performer in direct comparison. Its wins in both OpenCL and Vulkan benchmarks are the only performance metrics that matter for a head-to-head comparison. The 15.7% lead in Vulkan is not a marginal difference; it is a substantial gap that would translate to noticeably better performance in any application that leverages this API. For tasks that rely on compute or modern graphics pipelines, the K4000 is the card to choose.

However, the choice is not solely about raw speed. The K620 is a more power-efficient and compact option, with a TDP of 45 W compared to the K4000’s 80 W. The K620 also requires no power connectors, while the K4000 needs a single 6-pin connector. For a system with a limited power supply, such as the 200 W suggested for the K620 versus the 250 W for the K4000, the K620 is the safer bet. The K620’s smaller physical footprint (160 mm vs 241 mm) also makes it easier to fit into space-constrained chassis. The data suggests that the K4000 is for users who need maximum performance, while the K620 is for those who need a capable, low-profile solution that fits into tighter power and space envelopes.

Where Each One Wins

Based on the benchmark results, the NVIDIA Quadro K4000 wins in raw compute and graphics performance. Its decisive victory in the Geekbench Vulkan test (6964 vs 5870) indicates a strong advantage in applications that use this low-level, high-efficiency API, which is common in modern professional visualization and compute tasks. Its win in OpenCL, albeit narrow, also makes it the better choice for general-purpose GPU computing on that API. If the workload is performance-sensitive and the system can accommodate the card’s 80 W TDP and 6-pin power connector, the K4000 is the clear winner.

The NVIDIA Quadro K620 wins in scenarios where power consumption and physical size are critical constraints. Its 45 W TDP is nearly half that of the K4000, and its suggested PSU requirement of 200 W is 50 W lower. The K620 is a single-slot card that is significantly shorter (160 mm vs 241 mm) and less tall (69 mm vs 111 mm) than the K4000, making it ideal for small form factor workstations. Its lack of a power connector simplifies installation. While it loses the performance benchmarks, it is the only option that fits a specific set of system requirements. The K620’s performance is not negligible, as its OpenCL score of 6693 is within 1.8% of the K4000’s, meaning it can handle many compute tasks nearly as well while consuming far less power.

FAQ

Q: Which card performs better in the Geekbench Vulkan benchmark?

A: The NVIDIA Quadro K4000 significantly outperforms the K620 in the Vulkan test, scoring 6964 versus 5870, a 15.7% advantage.

Q: Is the NVIDIA Quadro K620 more power-efficient than the K4000?

A: Yes, the K620 has a TDP of 45 W compared to the K4000's 80 W. The K620 also requires no power connectors and has a lower suggested PSU of 200 W versus 250 W.

Q: What is the difference in memory bandwidth between the two cards?

A: The K4000 has a significantly higher memory bandwidth of 134.8 GB/s due to its 192-bit GDDR5 memory, while the K620 has 28.80 GB/s from its 128-bit DDR3 memory.

Q: Does the K620 have a higher average benchmark score than the K4000?

A: Yes, the K620 has an average benchmark score of 6282, which is higher than the K4000's 5982. However, this average includes a Geekbench Metal score for the K4000 that drags its average down.

Q: Which card has more shading units?

A: The NVIDIA Quadro K4000 has 768 shading units, which is double the K620's 384. This likely contributes to its higher benchmark scores.

Q: What is the launch MSRP of the K4000?

A: The NVIDIA Quadro K4000 had a launch MSRP of 1,269 USD.

Architecture Differences

The two cards are built on different architectures from NVIDIA. The K620 is based on the GM107 chip and uses the newer Maxwell architecture, while the K4000 is based on the GK106 chip and uses the older Kepler architecture. This architectural difference is central to their performance and feature set. The K620’s generation is listed as “Quadro Kepler (Kx200)”, which is a slight misnomer in the data, but its chip is definitively Maxwell. The K4000 is from the “Quadro Kepler (Kx000)” generation.

The transistor counts and die sizes reflect the different design philosophies. The K4000’s GK106 chip has 2,540 million transistors on a 221 mm² die, resulting in a transistor density of 11.5M / mm². The K620’s GM107 chip is smaller at 148 mm² but has 1,870 million transistors, achieving a higher density of 12.6M / mm². This suggests the Maxwell architecture is more efficient at packing transistors. The K4000 features a higher number of shaders (768 vs 384) and TMUs (64 vs 24), while the K620 has a lower ROPS count (16 vs 24). The raw compute power is also in the K4000’s favor, with an FP32 rate of 1,244.2 GFLOPS versus the K620’s 863.2 GFLOPS. The K620 does have a higher pixel rate (17.98 GPixel/s vs 12.96 GPixel/s) despite fewer ROPs, likely due to its higher clock speeds. The K620 also supports a newer version of Vulkan (1.4) compared to the K4000 (1.2.175), although this does not translate to better benchmark performance.

Specification Differences

The specification sheet reveals several key differences beyond the benchmarks. The most significant is the memory subsystem. The K4000 has 3 GB of GDDR5 memory on a 192-bit bus, providing 134.8 GB/s of bandwidth. The K620 has 2 GB of DDR3 memory on a 128-bit bus, yielding only 28.80 GB/s. This is a massive disparity in memory bandwidth, explaining the K4000’s superior performance in memory-intensive tasks. The K4000 also has a higher memory clock of 1404 MHz (5.6 Gbps effective) versus the K620’s 900 MHz (1800 Mbps effective).

The power requirements also differ substantially. The K620 has a TDP of 45 W, a single-slot design, and requires no power connectors. The K4000 has a TDP of 80 W, also a single-slot design, but requires a single 6-pin power connector. The suggested power supply is 200 W for the K620 and 250 W for the K4000. Physical dimensions are also different, with the K620 being much smaller at 160 mm in length and 69 mm in height, versus the K4000’s 241 mm length and 111 mm height. Both cards use a PCIe 2.0 x16 interface, but the K4000 offers more display outputs with 2x DisplayPort 1.2 and 1x DVI, compared to the K620’s single DisplayPort 1.2 and 1x DVI. The K4000 also has a higher base compute capability, evidenced by its higher FP32 performance and texture rate of 51.84 GTexel/s versus the K620’s 26.98 GTexel/s.