NVIDIA Quadro K4000M vs NVIDIA Quadro K620M Comparison

The NVIDIA Quadro K4000M and NVIDIA Quadro K620M are both end-of-life mobile workstation graphics solutions from NVIDIA, but they represent different architectural generations and performance tiers. The K4000M, released earlier, is a Kepler-based part with a larger die and higher power envelope, while the K620M is a Maxwell-based successor with a much smaller footprint and lower power draw. Despite these differences, their benchmark scores in the database are surprisingly close.

Head-to-Head Benchmarks

The only direct benchmark comparison available in the data is the Geekbench OpenCL test. In this test, the NVIDIA Quadro K4000M scores 5,986 points, while the NVIDIA Quadro K620M scores 5,957 points. The K4000M wins this head-to-head matchup with a delta of 0.5%. This is a narrow margin—essentially a statistical tie in real-world terms, as a 0.5% difference equates to just 29 points out of nearly 6,000.

Looking at the broader context of rival scores reinforces how close these two GPUs are. The K4000M’s nearest rivals include the AMD FirePro W4100 at 5,987 points (a 0% delta), the NVIDIA Quadro K4000 at 5,982 points (0.1% ahead), the NVIDIA RTX PRO 6000 Blackwell Server at 5,996 points (0.2% behind), and the NVIDIA GeForce GTX 770M at 6,000 points (0.2% behind). The K620M’s nearest rivals tell a similar story: the AMD Radeon HD 8730M at 5,955 points (0% delta), the AMD Radeon HD 8750M at 5,970 points (0.2% behind), the NVIDIA Quadro K4000 at 5,982 points (0.4% behind), and the Intel UHD Graphics 730 at 5,929 points (0.5% ahead).

The data shows that both cards sit in a dense cluster of GPUs scoring between roughly 5,900 and 6,000 points. The K4000M’s 5,986 score places it just ahead of the K620M’s 5,957, but both are within 1% of several rivals. The K4000M is 0.2% behind the GeForce GTX 770M and 0.2% behind the RTX PRO 6000 Blackwell Server, which is remarkable given the latter is a modern flagship. The K620M, meanwhile, is 0.5% ahead of the Intel UHD Graphics 730 integrated solution, showing that even a low-power discrete mobile GPU can outperform modern integrated graphics in this specific OpenCL workload.

Both GPUs land at the 34th percentile in the database’s overall ranking of all GPUs. This means that despite the architectural gulf between them—Kepler versus Maxwell, 3,540 million transistors versus 1,020 million—their actual compute performance in this benchmark is virtually indistinguishable. The K4000M’s win is real but marginal, and it does not indicate any meaningful performance advantage in practical terms.

Where Each One Wins

The K4000M wins the single benchmark test recorded, taking the Geekbench OpenCL crown with a 0.5% margin. This is its only win, and it holds up across the nearest rival comparisons as well. The K4000M also outperforms several competitors: it is 0.1% ahead of the NVIDIA Quadro K4000, 0.2% ahead of the RTX PRO 6000 Blackwell Server, and 0.2% ahead of the GeForce GTX 770M. It only trails the AMD FirePro W4100 by a negligible 0.1%.

The K620M wins no direct head-to-head tests in the data, as its 5,957 score falls short of the K4000M’s 5,986. However, it does hold its own against its own rival set. It is 0.5% ahead of the Intel UHD Graphics 730, matching the same margin by which it loses to the K4000M. The K620M is essentially tied with the AMD Radeon HD 8730M (0% delta) and trails the Radeon HD 8750M by 0.2% and the Quadro K4000 by 0.4%.

The K4000M’s advantage in raw compute can be attributed to its much larger hardware configuration. It packs 960 shading units, 80 texture mapping units, and 32 ROPs, alongside a 256-bit memory bus and 4 GB of GDDR5 memory. The K620M, by contrast, has 384 shading units, 16 TMUs, and 8 ROPs, with a 64-bit bus and 2 GB of DDR3 memory. The K4000M also has a higher pixel rate of 12.02 GPixel/s versus 8.992 GPixel/s, and a texture rate of 48.08 GTexel/s versus 17.98 GTexel/s. Its FP32 throughput of 1,153.9 GFLOPS dwarfs the K620M’s 863.2 GFLOPS.

Yet the benchmark results show that these massive specification advantages translate into only a 0.5% score improvement. This is likely because Geekbench OpenCL is not heavily dependent on memory bandwidth or texture throughput, and because the K620M’s much higher clock speeds—1,029 MHz base and 1,124 MHz boost, versus the K4000M’s flat 601 MHz—help close the gap. The K620M’s Maxwell architecture is also more efficient per clock than the older Kepler design.

The Verdict

For users choosing between these two based strictly on the benchmark data, the NVIDIA Quadro K4000M is the nominal winner. It scores higher in the Geekbench OpenCL test, and it also outperforms a wider range of rivals. The K4000M’s 5,986 score places it within 0.2% of the GeForce GTX 770M and RTX PRO 6000 Blackwell Server, while the K620M’s 5,957 leaves it slightly behind those same reference points.

However, the margin is so thin—0.5%, or 29 points—that it should not be the deciding factor in a real-world purchase decision. Both GPUs land at the 34th percentile, meaning they are statistically equivalent in this workload. The K4000M offers far more raw compute resources, but the K620M counters with higher clock speeds and a more modern architecture.

The K620M is the better choice for scenarios where power consumption matters. Its TDP of 30 W is one-third of the K4000M’s 100 W, and it uses a smaller MXM-A (3.0) interface versus the K4000M’s MXM-B (3.0). The K620M’s transistor density of 13.2M / mm² is also higher than the K4000M’s 12.0M / mm², reflecting the more efficient Maxwell design. For mobile workstations where battery life and thermal management are critical, the K620M’s lower power draw is a significant advantage.

The K4000M is the choice for users who prioritize the small performance edge and the larger memory configuration. With 4 GB of GDDR5 memory and a 256-bit bus, it has double the memory capacity and four times the bus width of the K620M. Its 89.60 GB/s of memory bandwidth is over five times the K620M’s 16.02 GB/s. For workloads that are sensitive to memory capacity or bandwidth—even if not reflected in the OpenCL benchmark—the K4000M is the more capable part.

FAQ

Q: Which GPU wins the Geekbench OpenCL benchmark?

A: The NVIDIA Quadro K4000M wins with a score of 5,986, beating the NVIDIA Quadro K620M’s 5,957 by a margin of 0.5%.

Q: How does the K4000M compare to the AMD FirePro W4100?

A: The K4000M scores 5,986, while the AMD FirePro W4100 scores 5,987, resulting in a 0% delta. The two are effectively tied.

Q: What is the transistor count difference between the two GPUs?

A: The K4000M uses 3,540 million transistors on a 294 mm² die, while the K620M uses 1,020 million transistors on a 77 mm² die.

Q: What is the memory bandwidth of each GPU?

A: The K4000M has a memory bandwidth of 89.60 GB/s, while the K620M has a memory bandwidth of 16.02 GB/s.

Q: Are both GPUs at the same performance percentile?

A: Yes, both the K4000M and the K620M are at the 34th percentile when compared to all GPUs in the database.

Q: What is the TDP of each GPU?

A: The K4000M has a TDP of 100 W, while the K620M has a TDP of 30 W.

Architecture Differences

The two GPUs are built on different architectures, which explains many of their specification gaps. The K4000M uses the GK104 chip based on NVIDIA’s Kepler architecture, fabricated by TSMC on a 28 nm process. It contains 3,540 million transistors on a die size of 294 mm², yielding a transistor density of 12.0M / mm². The K620M uses the GM108S chip based on the newer Maxwell architecture, also on a 28 nm process from TSMC. It packs 1,020 million transistors onto a much smaller 77 mm² die, resulting in a higher transistor density of 13.2M / mm².

The Kepler chip in the K4000M is a much larger, more complex design with 960 shading units, 80 TMUs, and 32 ROPs. The Maxwell chip in the K620M is more modest, with 384 shading units, 16 TMUs, and 8 ROPs. Neither GPU includes ray tracing cores or tensor cores, as both predate those features. The K4000M achieves a pixel rate of 12.02 GPixel/s and a texture rate of 48.08 GTexel/s, while the K620M manages 8.992 GPixel/s and 17.98 GTexel/s respectively. FP32 performance is 1,153.9 GFLOPS for the K4000M and 863.2 GFLOPS for the K620M.

The K4000M’s clock speeds are fixed at 601 MHz for both base and boost, with memory running at 700 MHz (2.8 Gbps effective). The K620M runs significantly higher clock speeds: 1,029 MHz base and 1,124 MHz boost, with memory at 1,001 MHz (2 Gbps effective). This clock advantage helps the smaller Maxwell chip stay competitive in the OpenCL benchmark. The K620M also supports a newer version of Vulkan (1.4) compared to the K4000M’s Vulkan 1.2.175, while both support DirectX 12 (11_0) and OpenGL 4.6.

Specification Differences

The two GPUs differ across nearly every major specification field. The K4000M has a larger memory configuration with 4 GB of GDDR5 memory on a 256-bit bus, delivering 89.60 GB/s of bandwidth. The K620M uses 2 GB of DDR3 memory on a 64-bit bus, with just 16.02 GB/s of bandwidth. This is the most significant practical difference between them, as the K4000M offers more capacity and over five times the bandwidth.

The K4000M’s TDP is 100 W, while the K620M draws only 30 W. Both use MXM modules, but the K4000M uses the MXM-B (3.0) interface while the K620M uses the smaller MXM-A (3.0) interface. Neither requires a power connector. Their display outputs are both marked as "Portable Device Dependent," meaning the actual ports depend on the laptop manufacturer.

The K4000M was released on 2012-05-31, while the K620M came later on 2015-02-28. Both are end-of-life products, and both share the same predecessor (Quadro Fermi-M) and successor (Quadro Maxwell-M). The K620M’s generation is listed as "Quadro Kepler-M (Kx200M)," which is a quirk in the data, as the chip itself is Maxwell-based. Both GPUs have no launch MSRP recorded in the database.

In terms of compute resources, the K4000M has 960 shading units, 80 TMUs, and 32 ROPs, while the K620M has 384 shading units, 16 TMUs, and 8 ROPs. The K4000M’s pixel rate is 12.02 GPixel/s versus 8.992 GPixel/s for the K620M. Texture rate is 48.08 GTexel/s versus 17.98 GTexel/s. FP32 throughput is 1,153.9 GFLOPS versus 863.2 GFLOPS. The K4000M also has a larger die (294 mm²) and more transistors (3,540 million) than the K620M (77 mm² and 1,020 million). The only specification where the K620M leads is transistor density (13.2M / mm² versus 12.0M / mm²), clock speeds (1,029/1,124 MHz versus 601/601 MHz), and Vulkan version support (1.4 versus 1.2.175).