AMD Radeon HD 6950 vs NVIDIA Quadro K4000M Comparison

# FAQ

Q: Which GPU has the higher Geekbench OpenCL score?

A: The AMD Radeon HD 6950 scores 6210, while the NVIDIA Quadro K4000M scores 5986. The AMD card wins this head-to-head by 3.7%.

Q: How does the AMD Radeon HD 6950 compare to its nearest rivals?

A: The HD 6950 sits at the 36th percentile among all GPUs. It trails the AMD FirePro W600 by 0.2%, the NVIDIA GeForce RTX 4070 Ti SUPER AD102 by 0.9%, and the NVIDIA GeForce RTX 5070 Ti SUPER by 0.9%, while sitting 1.1% behind the NVIDIA Quadro K620.

Q: Where does the NVIDIA Quadro K4000M rank among its closest competitors?

A: The K4000M holds the 34th percentile overall. It matches the AMD FirePro W4100 exactly, edges the NVIDIA Quadro K4000 by 0.1%, and sits 0.2% behind both the NVIDIA RTX PRO 6000 Blackwell Server and the NVIDIA GeForce GTX 770M.

Q: What are the transistor counts for each GPU?

A: The AMD Radeon HD 6950 packs 2,640 million transistors on a 389 mm² die, while the NVIDIA Quadro K4000M contains 3,540 million transistors on a 294 mm² die. The K4000M achieves a higher transistor density at 12.0M per mm² versus 6.8M per mm².

Q: Which card has higher pixel and texture fill rates?

A: The AMD Radeon HD 6950 delivers 25.60 GPixel/s and 70.40 GTexel/s, both substantially above the K4000M's 12.02 GPixel/s and 48.08 GTexel/s.

Q: What are the memory specifications of each card?

A: The Radeon HD 6950 has 2 GB GDDR5 on a 256-bit bus with 160.0 GB/s bandwidth and 5 Gbps effective memory speed. The Quadro K4000M has 4 GB GDDR5 on a 256-bit bus with 89.60 GB/s bandwidth and 2.8 Gbps effective memory speed.

Architecture Differences

The AMD Radeon HD 6950 and NVIDIA Quadro K4000M represent fundamentally different design philosophies from two competing architectures. The HD 6950 uses the Cayman chip built on TeraScale 3 architecture, part of the Northern Islands (HD 6900) generation, fabricated on a 40 nm process at TSMC. In contrast, the K4000M employs the GK104 chip under NVIDIA's Kepler architecture, belonging to the Quadro Kepler-M (Kx000M) generation, also built by TSMC but on a more advanced 28 nm process.

The process node difference is significant: 40 nm versus 28 nm. This allowed NVIDIA to pack 3,540 million transistors into a 294 mm² die, achieving a transistor density of 12.0M per mm². AMD's larger 389 mm² die holds fewer transistors at 2,640 million, yielding a density of only 6.8M per mm². The Kepler architecture's efficiency advantage is clear from these density figures.

Shading unit counts differ markedly. The Radeon HD 6950 features 1,408 shading units, 88 texture mapping units, and 32 ROPs. The Quadro K4000M has 960 shading units, 80 TMUs, and also 32 ROPs. AMD's shader-heavy design contributes to its higher raw compute throughput, while NVIDIA's Kepler architecture relies on architectural efficiency rather than sheer unit count.

Memory subsystems diverge in capacity and bandwidth. Both use GDDR5 on 256-bit buses, but the HD 6950 provides 2 GB at 160.0 GB/s, while the K4000M offers double the capacity at 4 GB but with significantly lower bandwidth at 89.60 GB/s. Memory clocks reflect this: 5 Gbps effective for AMD versus 2.8 Gbps effective for NVIDIA.

API support shows generational differences. The HD 6950 supports DirectX 11.2 (11_0), OpenGL 4.4, and no Vulkan. The K4000M supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175. This reflects the K4000M's later release date and more modern driver stack.

Power characteristics diverge sharply. The Radeon HD 6950 carries a 200 W TDP, requires dual-slot cooling, needs 2x 6-pin power connectors, and recommends a 550 W PSU. The Quadro K4000M is an MXM Module with a 100 W TDP, no power connectors, and no suggested PSU rating—it is designed for mobile workstations.

Physical specifications also differ. The HD 6950 is 286 mm long, 126 mm tall, and 42 mm wide, while the K4000M has no listed dimensions due to its MXM-B (3.0) form factor. Display outputs reflect their intended markets: the HD 6950 offers 2x DVI, 1x HDMI 1.4a, and 2x mini-DisplayPort 1.2, while the K4000M's outputs are portable device dependent.

Head-to-Head Benchmarks

The single available benchmark comparison is Geekbench OpenCL, and it produces a clear but modest victory for the AMD Radeon HD 6950. The HD 6950 scores 6210 against the K4000M's 5986, a 3.7% delta in AMD's favor. This is a narrow margin—not a dominant win, but a consistent one.

Context from the nearest rivals table sharpens the picture. The HD 6950's 6210 score places it in a cluster of GPUs scoring between 6223 and 6270. It is nearly tied with the AMD FirePro W600 (6223, just 0.2% ahead), and trails the NVIDIA GeForce RTX 4070 Ti SUPER AD102 and RTX 5070 Ti SUPER (both 6270, 0.9% ahead) by less than one percent. The NVIDIA Quadro K620 at 6282 sits 1.1% higher. This means the HD 6950 is competitive with much newer and more expensive GPUs in OpenCL compute workloads, despite its age.

The K4000M's 5986 score places it in an even tighter cluster. It matches the AMD FirePro W4100 exactly (5987, 0% delta), sits 0.1% above the NVIDIA Quadro K4000 (5982), and trails the NVIDIA RTX PRO 6000 Blackwell Server (5996) and GeForce GTX 770M (6000) by 0.2% each. The K4000M is essentially tied with all four rivals, indicating that its compute performance is well within the expected range for its class.

The percentile rankings reinforce the head-to-head result. The HD 6950 ranks at the 36th percentile among all GPUs, while the K4000M sits at the 34th percentile. Both are below the median, but the HD 6950's relative standing is two percentage points higher.

When interpreting the 3.7% delta, it is important to note that the HD 6950 achieves this with 2 GB of memory versus the K4000M's 4 GB, and with a 200 W TDP versus 100 W. The AMD card delivers higher compute throughput per watt in this specific benchmark, though the K4000M's lower power draw makes it more suitable for thermally constrained environments.

Specification Differences

| Specification | AMD Radeon HD 6950 | NVIDIA Quadro K4000M |

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

| Architecture | TeraScale 3 | Kepler |

| Process Node | 40 nm | 28 nm |

| Transistors | 2,640 million | 3,540 million |

| Die Size | 389 mm² | 294 mm² |

| Transistor Density | 6.8M / mm² | 12.0M / mm² |

| Memory Clock | 1250 MHz / 5 Gbps effective | 700 MHz / 2.8 Gbps effective |

| Memory Size | 2 GB | 4 GB |

| Memory Bandwidth | 160.0 GB/s | 89.60 GB/s |

| Shading Units | 1408 | 960 |

| TMUs | 88 | 80 |

| Pixel Rate | 25.60 GPixel/s | 12.02 GPixel/s |

| Texture Rate | 70.40 GTexel/s | 48.08 GTexel/s |

| FP32 | 2.253 TFLOPS | 1,153.9 GFLOPS |

| TDP | 200 W | 100 W |

| Slot Width | Dual-slot | MXM Module |

| Power Connectors | 2x 6-pin | None |

| Suggested PSU | 550 W | None |

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

| Display Outputs | 2x DVI, 1x HDMI 1.4a, 2x mini-DisplayPort 1.2 | Portable Device Dependent |

| DirectX | 11.2 (11_0) | 12 (11_0) |

| OpenGL | 4.4 | 4.6 |

| Vulkan | None | 1.2.175 |

| Dimensions | 286 mm x 126 mm x 42 mm | Not specified |

| Release Date | 2010-12-13 | 2012-05-31 |

Where Each One Wins

The AMD Radeon HD 6950 wins in raw compute throughput. Its 2.253 TFLOPS FP32 performance dwarfs the K4000M's 1,153.9 GFLOPS—a difference of nearly 2x. The pixel rate of 25.60 GPixel/s versus 12.02 GPixel/s and texture rate of 70.40 GTexel/s versus 48.08 GTexel/s further demonstrate AMD's advantage in fill-rate-bound workloads. The 160.0 GB/s memory bandwidth versus 89.60 GB/s means the HD 6950 can feed its shader array more effectively in bandwidth-intensive tasks. For OpenCL compute workloads, the HD 6950's 6210 score versus 5986 confirms its edge.

The NVIDIA Quadro K4000M wins in efficiency and capacity. Its 100 W TDP is exactly half the HD 6950's 200 W, making it suitable for mobile workstations where power and thermal envelopes are tight. The 4 GB memory capacity doubles the HD 6950's 2 GB, which matters for workloads with large working sets that exceed 2 GB. The K4000M also supports newer API versions: DirectX 12 versus 11.2, OpenGL 4.6 versus 4.4, and Vulkan 1.2.175 versus no Vulkan support at all. The MXM-B (3.0) form factor enables integration into laptops, while the HD 6950 requires a desktop PCIe 2.0 x16 slot.

The transistor density advantage belongs to NVIDIA. At 12.0M per mm² versus 6.8M per mm², the Kepler architecture is more efficient at packing transistors onto the die, which contributes to the K4000M's lower power draw and smaller footprint. The 28 nm process versus 40 nm also gives NVIDIA a generational manufacturing advantage.

The Verdict

The data supports a clear split based on use case. The AMD Radeon HD 6950 is the stronger compute performer. Its 3.7% OpenCL benchmark win, higher pixel rate (25.60 versus 12.02 GPixel/s), higher texture rate (70.40 versus 48.08 GTexel/s), and nearly double the FP32 throughput (2.253 TFLOPS versus 1,153.9 GFLOPS) make it the pick for raw number-crunching tasks. Its 160.0 GB/s memory bandwidth is also 79% higher than the K4000M's 89.60 GB/s, reducing memory bottlenecks in data-heavy workloads. The HD 6950's 36th percentile ranking versus the K4000M's 34th percentile confirms its relative standing.

However, the Quadro K4000M wins on practical deployment grounds. Its 100 W TDP makes it feasible in environments where the HD 6950's 200 W requirement would be prohibitive. The 4 GB memory capacity is double the HD 6950's 2 GB, a decisive advantage for workloads that do not fit within 2 GB. The newer API support—DirectX 12, OpenGL 4.6, and Vulkan 1.2.175—ensures compatibility with modern software stacks, while the HD 6950 lacks Vulkan entirely and caps at OpenGL 4.4. The MXM-B (3.0) form factor allows the K4000M to operate in mobile workstations, whereas the HD 6950 is a desktop-only dual-slot card.

For users prioritizing compute performance and memory bandwidth in a desktop environment, the AMD Radeon HD 6950 is the data-backed choice. For users needing mobile deployment, lower power consumption, larger memory capacity, or modern API support, the NVIDIA Quadro K4000M is the appropriate selection. The 3.7% benchmark delta is real but small; the fundamental decision hinges on form factor, power envelope, and API requirements rather than raw speed. Both GPUs are end-of-life products, but their respective strengths address different segments of the market.