NVIDIA Quadro K4000 vs NVIDIA Quadro K620M Comparison

NVIDIA’s Quadro K4000 and Quadro K620M represent two distinct approaches to professional mobile and desktop graphics, separated by two years of architecture evolution. The K4000 is a full-size desktop card built on the Kepler architecture, while the K620M is a low-power MXM module for laptops. Benchmark data shows a clear, if narrow, overall performance advantage for the K4000, but the K620M counters with dramatically better efficiency and a more modern feature set. This analysis breaks down the head-to-head results, architectural divergences, and the specific use cases where each GPU holds an edge.

Head-to-Head Benchmarks

The only directly comparable benchmark in the data set is Geekbench OpenCL, and it delivers a decisive win for the older desktop card. The Quadro K4000 scores 6,816 points, while the Quadro K620M manages 5,957 points. That is a 14.4% advantage for the K4000, a margin that is substantial in the context of professional workloads where every bit of compute throughput matters. The K4000’s lead is not a near-run thing; it is a comfortable gap that places the two cards in different performance tiers despite their adjacent average scores.

Looking at the broader average benchmark scores, the K4000 posts 5,982 points across all tests, edging out the K620M’s 5,957 points. The delta here is a mere 0.4%, which might suggest near-parity. However, that average is skewed by the K620M having only a single benchmark entry in the dataset (OpenCL), whereas the K4000 also includes Metal and Vulkan results. When isolating the one shared test, the K4000’s 14.4% victory is the true indicator of compute capability. The K4000 also holds a 0.2% advantage over the AMD Radeon HD 8750M in its nearest rival list, while the K620M sits 0.2% behind that same Radeon part, reinforcing the hierarchy.

In terms of raw throughput metrics from the specification sheet, the K4000’s FP32 performance is listed at 1,244.2 GFLOPS versus 863.2 GFLOPS for the K620M — a 44% gap in theoretical peak floating-point output. Texture rate tells a similar story: 51.84 GTexel/s for the K4000 against 17.98 GTexel/s for the K620M. Pixel rate also favors the desktop card at 12.96 GPixel/s versus 8.992 GPixel/s. These numbers are not directly benchmarked, but they align with the OpenCL result and explain why the K4000 wins. The K620M’s single benchmark win count is zero; the K4000 takes the sole head-to-head crown.

Architecture Differences

The two GPUs are built on different architectures despite sharing a 28 nm TSMC process node. The K4000 uses the GK106 chip under the Kepler architecture, while the K620M employs the GM108S chip with the Maxwell architecture. This generational shift is significant. Kepler was NVIDIA’s first unified architecture for the Quadro line, but Maxwell brought substantial efficiency improvements and newer feature support. The K4000 belongs to the Quadro Kepler (Kx000) generation, while the K620M is listed under the Quadro Kepler-M (Kx200M) generation — a naming oddity that nonetheless reflects its Maxwell internals.

The transistor counts differ massively. The K4000 packs 2,540 million transistors on a 221 mm² die, yielding a transistor density of 11.5M per mm². The K620M, by contrast, has just 1,020 million transistors on a 77 mm² die, but achieves a higher density of 13.2M per mm². That density improvement is a hallmark of the Maxwell architecture’s design efficiency. In practical terms, the K620M delivers a meaningful fraction of the K4000’s performance while using far fewer transistors and occupying a fraction of the silicon area.

Clock behavior also differs. The K4000’s base and boost clocks are not listed in the data, but its memory runs at 1404 MHz with an effective data rate of 5.6 Gbps. The K620M has explicit base and boost clocks of 1029 MHz and 1124 MHz respectively, with memory at 1001 MHz and an effective rate of 2 Gbps. The K620M’s memory is DDR3 rather than GDDR5, and its bus width is a narrow 64-bit compared to the K4000’s 192-bit bus. This results in a stark memory bandwidth disparity: 134.8 GB/s for the K4000 versus just 16.02 GB/s for the K620M — an 8.4x difference that heavily impacts memory-bound workloads.

The API support shows the Maxwell part’s newer lineage. Both support DirectX 12 (11_0) and OpenGL 4.6, but the K620M supports Vulkan 1.4, while the K4000 is limited to Vulkan 1.2.175. This is a meaningful advantage for the K620M in modern applications that leverage newer Vulkan extensions. The K4000 compensates with more shading units (768 versus 384), more TMUs (64 versus 16), and more ROPs (24 versus 8), which explains its superior fill rates and compute throughput.

Where Each One Wins

The K4000 is the clear winner for raw compute and rendering throughput. Its 14.4% OpenCL lead, coupled with 44% higher FP32 output, makes it the better choice for GPU-accelerated simulations, rendering tasks, and any workload that saturates the shading units or memory subsystem. The 134.8 GB/s of bandwidth is a critical asset for large textures and datasets; the K620M’s 16.02 GB/s would bottleneck such workloads severely. The K4000’s 3 GB GDDR5 frame buffer also provides more headroom for complex scenes than the K620M’s 2 GB DDR3.

However, the K620M wins decisively on efficiency and integration. Its 30 W TDP is a fraction of the K4000’s 80 W, and it requires no power connectors, drawing everything from the MXM slot. The K4000 needs a 1x 6-pin connector and a suggested 250 W power supply. In a mobile workstation, the K620M’s power draw is a decisive factor; it enables thinner, lighter laptops with longer battery life. The K620M is an MXM-A (3.0) module with portable-device-dependent display outputs, whereas the K4000 is a single-slot card with 1x DVI and 2x DisplayPort 1.2 outputs. For a fixed desktop workstation, the K4000’s dedicated display outputs and larger footprint are non-issues.

The K620M also wins on modern API readiness. Its Vulkan 1.4 support versus the K4000’s Vulkan 1.2.175 means better forward-compatibility with newer software stacks. In applications that are not memory-bandwidth-limited but rely on current driver optimizations and API features, the K620M can punch above its weight class. The K4000’s higher pixel and texture rates (12.96 GPixel/s and 51.84 GTexel/s) make it the better choice for traditional rasterization-heavy tasks, but the K620M’s efficiency profile suits remote workstations, portable CAD, and power-constrained environments.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The NVIDIA Quadro K4000 has an average benchmark score of 5,982, while the Quadro K620M scores 5,957. The K4000 leads by 0.4%, but this figure aggregates different test sets; the only shared test (Geekbench OpenCL) shows a 14.4% lead for the K4000.

Q: How do the two GPUs compare in memory bandwidth?

A: The K4000 has a massive advantage at 134.8 GB/s, using a 192-bit bus with GDDR5 memory. The K620M is limited to 16.02 GB/s via a 64-bit bus with DDR3 memory. This is an 8.4x difference in favor of the K4000.

Q: What are the TDP requirements for each card?

A: The K4000 has a TDP of 80 W and requires a 1x 6-pin power connector plus a suggested 250 W PSU. The K620M has a TDP of 30 W and needs no power connectors, drawing power solely from the MXM slot.

Q: Which GPU supports a newer Vulkan version?

A: The Quadro K620M supports Vulkan 1.4, whereas the Quadro K4000 supports Vulkan 1.2.175. Both offer DirectX 12 (11_0) and OpenGL 4.6.

Q: What is the transistor count and die size difference?

A: The K4000 uses 2,540 million transistors on a 221 mm² die (11.5M / mm² density). The K620M uses 1,020 million transistors on a 77 mm² die (13.2M / mm² density). The K620M is smaller but denser.

Q: How does the K4000 compare to the K620M in raw compute throughput?

A: The K4000 delivers 1,244.2 GFLOPS FP32 performance, compared to 863.2 GFLOPS for the K620M. This represents a 44% advantage for the K4000 in theoretical peak floating-point output, consistent with its 14.4% OpenCL benchmark win.

Specification Differences

The following table highlights the key fields where the two GPUs differ, based solely on the provided data.

| Specification | NVIDIA Quadro K4000 | NVIDIA Quadro K620M |

|---|---|---|

| Chip | GK106 | GM108S |

| Architecture | Kepler | Maxwell |

| Generation | Quadro Kepler (Kx000) | Quadro Kepler-M (Kx200M) |

| Process Node | 28 nm | 28 nm |

| Transistors | 2,540 million | 1,020 million |

| Die Size | 221 mm² | 77 mm² |

| Transistor Density | 11.5M / mm² | 13.2M / mm² |

| Base Clock | Not listed | 1029 MHz |

| Boost Clock | Not listed | 1124 MHz |

| Memory Clock | 1404 MHz (5.6 Gbps effective) | 1001 MHz (2 Gbps effective) |

| Memory Size | 3 GB | 2 GB |

| Memory Type | GDDR5 | DDR3 |

| Memory Bus Width | 192 bit | 64 bit |

| Memory Bandwidth | 134.8 GB/s | 16.02 GB/s |

| Shading Units | 768 | 384 |

| TMUs | 64 | 16 |

| ROPs | 24 | 8 |

| Pixel Rate | 12.96 GPixel/s | 8.992 GPixel/s |

| Texture Rate | 51.84 GTexel/s | 17.98 GTexel/s |

| FP32 (Single Precision) | 1,244.2 GFLOPS | 863.2 GFLOPS |

| TDP | 80 W | 30 W |

| Slot Width | Single-slot | MXM Module |

| Power Connectors | 1x 6-pin | None |

| Suggested PSU | 250 W | Not listed |

| Bus Interface | PCIe 2.0 x16 | MXM-A (3.0) |

| Display Outputs | 1x DVI, 2x DisplayPort 1.2 | Portable Device Dependent |

| Vulkan Version | 1.2.175 | 1.4 |

| Release Date | 2013-02-28 | 2015-02-28 |

| Launch MSRP | 1,269 USD | Not listed |

| Geekbench OpenCL Score | 6,816 | 5,957 |