NVIDIA Quadro K6000 vs NVIDIA Quadro RTX 4000 Comparison

The NVIDIA Quadro K6000 and NVIDIA Quadro RTX 4000 represent two distinct eras of professional workstation graphics. The K6000, launched in mid-2013, is a Kepler-generation behemoth built for raw compute throughput, while the RTX 4000, from late 2018, introduces Turing architecture features like real-time ray tracing and tensor cores. The benchmark data reveals a stark generational divide, with the newer card dominating in every head-to-head test, yet the older card still holds its own in specific legacy workloads. This analysis breaks down exactly where each card excels, using only the provided benchmark scores and specifications.

Head-to-Head Benchmarks

The data available for direct comparison is limited to two OpenCL and Vulkan compute tests, and the results are unequivocal. In the Geekbench OpenCL test, the Quadro RTX 4000 scores 74,540 points, obliterating the K6000’s 23,749 points. This represents a massive 68.1% delta in favor of the RTX 4000. Similarly, in the Geekbench Vulkan test, the RTX 4000 achieves 78,844 points against the K6000’s 25,409 points, a 67.8% advantage. These are not marginal improvements; they are generational leaps in raw compute throughput.

The magnitude of these wins is worth contextualizing. The RTX 4000’s OpenCL score is more than triple that of the K6000. This suggests that the newer card’s architecture is significantly more efficient at handling the parallel workloads that these APIs represent. The Vulkan results follow the same pattern, reinforcing that the Turing architecture provides a substantial uplift in general-purpose GPU compute. The K6000, despite its higher shading unit count (2,880 vs. 2,304), cannot compensate for the RTX 4000’s higher clock speeds and architectural improvements.

The head-to-head table shows zero wins for the K6000 and two wins for the RTX 4000. This is a clean sweep. However, it is crucial to note that these tests do not represent all possible workloads. The K6000’s average benchmark score across all its tested workloads is 19,030, while the RTX 4000’s average is 17,789. Interestingly, the K6000’s average is actually higher than the RTX 4000’s, despite losing both head-to-head tests. This discrepancy suggests that the K6000 excels in some benchmark categories where the RTX 4000 was not tested, or that the RTX 4000’s average is dragged down by its weaker DirectX 9 and DirectX 10 PassMark scores (205 and 108, respectively), which are likely not relevant to professional workstation tasks.

FAQ

Q: Which card has a higher raw compute performance in compute APIs?

A: The NVIDIA Quadro RTX 4000 is decisively faster. It leads by 68.1% in Geekbench OpenCL (74,540 vs. 23,749) and by 67.8% in Geekbench Vulkan (78,844 vs. 25,409). The data indicates the Turing architecture provides a massive performance advantage in these modern compute interfaces.

Q: Does the older K6000 have any performance advantage?

A: Yes, in its average benchmark score. The K6000 has an average benchmark score of 19,030 compared to the RTX 4000’s 17,789. This suggests that across all its tested legacy workloads (including DirectX 9, 10, and 11 PassMark tests), the K6000 performs better, even though it loses in the modern compute APIs.

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

A: The K6000 has a larger 12 GB memory pool using GDDR5 on a 384-bit bus, providing 288.4 GB/s of bandwidth. The RTX 4000 has 8 GB of GDDR6 on a narrower 256-bit bus, yet delivers significantly higher bandwidth at 416.0 GB/s due to its faster 13 Gbps effective memory speed.

Q: Which card supports newer graphics APIs like DirectX 12 Ultimate?

A: Only the Quadro RTX 4000 supports DirectX 12 Ultimate (12_2). The K6000 is limited to DirectX 12 (11_1). Both cards support OpenGL 4.6, but the RTX 4000 has a newer Vulkan version (1.4) compared to the K6000’s 1.2.175.

Q: How do the power requirements differ?

A: The RTX 4000 is far more power-efficient. It has a 160 W TDP and requires a single 8-pin power connector with a suggested 450 W PSU. The K6000 has a 225 W TDP, requires two 6-pin connectors, and suggests a 550 W PSU. The RTX 4000 also fits in a single-slot form factor, while the K6000 is dual-slot.

Q: What is the transistor density difference between the two architectures?

A: The RTX 4000’s Turing chip (TU104) has a density of 25.0M transistors per mm², nearly double the K6000’s Kepler chip (GK110B) at 12.6M per mm². This is despite the RTX 4000 having a smaller die size (545 mm² vs. 561 mm²) and a more advanced 12 nm process node compared to the K6000’s 28 nm node.

Where Each One Wins

The RTX 4000 is the clear winner in modern compute APIs. Its staggering 68.1% lead in OpenCL and 67.8% lead in Vulkan makes it the obvious choice for any application that leverages these interfaces, which includes most contemporary rendering engines, machine learning frameworks, and scientific computing packages. The data strongly implies that for current-generation software, the RTX 4000 is vastly superior.

The K6000’s win is more subtle but still evident. Its higher average benchmark score (19,030 vs. 17,789) indicates that in a suite of legacy benchmarks—particularly its PassMark DirectX 9 score of 205, DirectX 10 score of 108, and DirectX 11 score of 128—it outperforms the RTX 4000’s corresponding scores (52, 108, and 128 for DX9, DX10, DX11 respectively). While the RTX 4000 wins on DirectX 12 (52 vs. N/A for K6000), the K6000’s strength in older DirectX versions suggests it may be better suited for legacy professional applications that rely on those older APIs. The K6000’s larger 12 GB memory pool also provides a capacity advantage for datasets that exceed 8 GB, even if the bandwidth is lower.

Specification Differences

The two cards differ fundamentally in nearly every specification category. The RTX 4000 has a higher base clock (1005 MHz vs. 797 MHz) and a much higher boost clock (1545 MHz vs. 902 MHz). The K6000 has more shading units (2,880 vs. 2,304) and texture mapping units (240 vs. 144), but the RTX 4000 has more ROPs (64 vs. 48). The RTX 4000 also features dedicated hardware that the K6000 lacks entirely: 36 RT cores and 288 tensor cores.

Memory specifications show a clear trade-off. The K6000 has 12 GB of GDDR5 on a 384-bit bus, while the RTX 4000 has 8 GB of GDDR6 on a 256-bit bus. The RTX 4000’s memory is faster at 1625 MHz (13 Gbps effective) yielding 416.0 GB/s bandwidth, compared to the K6000’s 1502 MHz (6 Gbps effective) and 288.4 GB/s. The cards also differ significantly in physical requirements: the RTX 4000 is single-slot with a 160 W TDP and one 8-pin connector, while the K6000 is dual-slot with a 225 W TDP and two 6-pin connectors. The RTX 4000 is also shorter at 241 mm versus the K6000’s 267 mm.

Display outputs also differ. The RTX 4000 offers 3x DisplayPort 1.4a and 1x USB Type-C, while the K6000 offers 2x DVI and 2x DisplayPort 1.2. The RTX 4000 supports a newer DirectX version (12 Ultimate vs. 11_1) and a newer Vulkan version (1.4 vs. 1.2.175). The transistor counts are drastically different too: the RTX 4000 packs 13,600 million transistors on a 545 mm² die, while the K6000 has 7,080 million on a 561 mm² die.

Architecture Differences

The architectural divide is profound. The K6000 is built on the Kepler architecture using the GK110B chip, fabricated on a 28 nm process at TSMC. In contrast, the RTX 4000 uses the Turing architecture with the TU104 chip, fabricated on a 12 nm process, also at TSMC. This process shrink allows the RTX 4000 to achieve a transistor density of 25.0M / mm², nearly double the K6000’s 12.6M / mm².

The most significant architectural addition in the RTX 4000 is the inclusion of 36 RT cores and 288 tensor cores. These are absent from the K6000 entirely. RT cores are dedicated to ray tracing calculations, while tensor cores accelerate AI and deep learning workloads. The K6000 has no such specialized hardware. The RTX 4000 also supports FP16 computation at 14.24 TFLOPS (2:1 ratio), whereas the K6000 has no listed FP16 capability, focusing solely on FP32 at 5.196 TFLOPS. The RTX 4000’s FP32 performance is higher at 7.119 TFLOPS.

The pixel and texture rates reflect these changes. The RTX 4000 achieves 98.88 GPixel/s, nearly double the K6000’s 54.12 GPixel/s. The texture rate is closer, with the RTX 4000 at 222.5 GTexel/s versus the K6000’s 216.5 GTexel/s. The memory architecture also differs, with the RTX 4000 using GDDR6 and the K6000 using GDDR5. The RTX 4000’s support for DirectX 12 Ultimate and Vulkan 1.4 indicates a much more modern feature set, while the K6000 is limited to DirectX 12 (11_1) and Vulkan 1.2.175.

The Verdict

The data is unambiguous for modern workloads: the Quadro RTX 4000 is the superior choice. Its 68.1% lead in OpenCL and 67.8% lead in Vulkan benchmarks demonstrate a decisive performance advantage in the compute APIs that power contemporary professional applications. For users running current CAD, DCC, or scientific software that leverages these APIs, the RTX 4000 is the only logical pick. The addition of RT and tensor cores also makes it future-proof for ray-traced rendering and AI-accelerated tasks, which the K6000 cannot handle.

However, the K6000 is not obsolete. Its higher average benchmark score (19,030 vs. 17,789) suggests that in a broader set of legacy tests, particularly older DirectX workloads, it holds its own. The 12 GB memory pool is also 50% larger than the RTX 4000’s 8 GB, which could be critical for specific datasets that fit within that larger frame buffer. For users maintaining legacy applications that are not optimized for Vulkan or modern OpenCL, and where memory capacity trumps bandwidth, the K6000 may still be a viable option. Its end-of-life status and 2013 release date, however, mean that software support will increasingly favor the newer architecture. Ultimately, the choice depends on the software stack: the RTX 4000 is for the present and future, while the K6000 is a relic that still works for a shrinking set of old tasks.