AMD Radeon HD 6950 vs NVIDIA Quadro K620M Comparison

Head-to-Head Benchmarks

The only direct benchmark comparison available is the Geekbench OpenCL test, and it favors the AMD Radeon HD 6950 by a noticeable margin. The AMD card scores 6210 points, while the NVIDIA Quadro K620M manages 5957 points. That works out to a 4.2% delta in favor of the AMD part — a meaningful gap in this specific compute workload, though not a blowout. In practical terms, the HD 6950 completes the same OpenCL tasks roughly 4% faster than the Quadro K620M.

Looking at the broader competitive landscape reinforces this positioning. The HD 6950 sits at the 36th percentile of all GPUs, with its 6210 average score placing it just 0.2% behind the AMD FirePro W600 (6223) and 0.9% behind the NVIDIA GeForce RTX 4070 Ti SUPER AD102 (6270). The Quadro K620M, by contrast, sits at the 34th percentile with its 5957 average. Its nearest rivals include the AMD Radeon HD 8730M at 5955 (0.0% delta) and the Intel UHD Graphics 730 at 5929 (0.5% delta in the Quadro's favor).

The delta between the two cards in this head-to-head is larger than the delta between the K620M and several of its own closest rivals. For instance, the K620M is only 0.4% behind the NVIDIA Quadro K4000 (5982) and 0.2% behind the AMD Radeon HD 8750M (5970). Meanwhile, the gap between the HD 6950 and the K620M is 4.2%. That means the difference between these two cards is more pronounced than the differences separating the K620M from its immediate competition.

One thing to note: the HD 6950's nearestRivals list includes some very modern, high-end parts like the RTX 4070 Ti SUPER AD102 and RTX 5070 Ti SUPER, both scoring 6270. The HD 6950 trails those by just 0.9%. That seems counterintuitive given the age and architecture of the AMD card, but the data is what it is — in this specific OpenCL test, the HD 6950 is within striking distance of those newer GPUs, while the K620M is not.

The K620M's closest comparable in terms of score is actually the Intel UHD Graphics 730, which trails by only 0.5%. That puts the Quadro in a very different performance class than the HD 6950. The AMD card is competing with workstation and desktop parts in the 6200-6300 range; the NVIDIA part is competing with integrated and mobile graphics in the 5900-6000 range.

The Verdict

The data points in one direction: the AMD Radeon HD 6950 is the faster card in OpenCL compute workloads. With a 4.2% lead over the Quadro K620M, and a 36th percentile ranking versus the Quadro's 34th, the HD 6950 wins the only head-to-head benchmark available. If raw compute performance is the sole criterion, the choice is clear.

However, the Quadro K620M has advantages that the benchmark doesn't capture. Its 30 W TDP versus the HD 6950's 200 W TDP is a massive difference in power draw. The Quadro is an MXM module with no power connectors, while the HD 6950 is a dual-slot card requiring 2x 6-pin connectors and a 550 W suggested PSU. For a small form factor or mobile workstation, the Quadro is the only realistic option — the HD 6950's 286 mm length and dual-slot footprint simply won't fit in those chassis.

The HD 6950 is the pick for anyone building a desktop system where power and space are not constraints, and where OpenCL performance is the priority. The Quadro K620M is the pick for portable or compact systems that need a discrete GPU without the power and thermal overhead. The HD 6950's 2.253 TFLOPS FP32 throughput dwarfs the Quadro's 863.2 GFLOPS, but that compute advantage comes at the cost of over six times the power draw.

Neither card is current — both are end-of-life products. But for legacy systems, the HD 6950 offers substantially more compute headroom. The Quadro's advantage is efficiency and form factor, not performance.

Architecture Differences

The architectural divide between these two is stark. The AMD Radeon HD 6950 uses the Cayman chip built on TeraScale 3, a 40 nm design from TSMC. The NVIDIA Quadro K620M uses the GM108S chip built on Maxwell, also from TSMC but on a newer 28 nm process. That process advantage shows in transistor density: the K620M packs 13.2 million transistors per mm² versus the HD 6950's 6.8 million per mm². The HD 6950 has more total transistors (2,640 million versus 1,020 million) and a much larger die (389 mm² versus 77 mm²), but the Quadro is far more density-efficient.

The HD 6950 belongs to the Northern Islands (HD 6900) generation and is the successor to Evergreen, with Southern Islands as its successor. The Quadro K620M is listed under the Quadro Kepler-M (Kx200M) generation, with Quadro Fermi-M as its predecessor and Quadro Maxwell-M as its successor. Despite the "Kepler-M" generation label, the chip itself is Maxwell architecture.

Compute resources differ enormously. The HD 6950 has 1408 shading units, 88 TMUs, and 32 ROPs. The Quadro K620M has 384 shading units, 16 TMUs, and 8 ROPs. The HD 6950's pixel rate of 25.60 GPixel/s is nearly three times the Quadro's 8.992 GPixel/s. Texture rate is similarly lopsided: 70.40 GTexel/s versus 17.98 GTexel/s.

Memory architecture is another major divergence. The HD 6950 uses 2 GB of GDDR5 on a 256-bit bus, delivering 160.0 GB/s of bandwidth. The Quadro K620M uses 2 GB of DDR3 on a 64-bit bus, delivering just 16.02 GB/s — one-tenth the bandwidth. Memory clock rates reflect this: the HD 6950 runs at 1250 MHz (5 Gbps effective), while the Quadro runs at 1001 MHz (2 Gbps effective).

API support favors the Quadro in some areas. The K620M supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.4. The HD 6950 supports DirectX 11.2 (11_0) and OpenGL 4.4, with no Vulkan support listed. The Quadro is also a newer product, released in February 2015 versus December 2010 for the HD 6950.

FAQ

Q: Which card has higher raw compute performance?

A: The AMD Radeon HD 6950. It scores 6210 in Geekbench OpenCL versus 5957 for the Quadro K620M, a 4.2% advantage. Its FP32 throughput is 2.253 TFLOPS compared to 863.2 GFLOPS for the Quadro.

Q: Which card is more power-efficient?

A: The NVIDIA Quadro K620M by a wide margin. Its TDP is 30 W, versus 200 W for the HD 6950. The Quadro requires no power connectors and is an MXM module, while the HD 6950 needs 2x 6-pin connectors and a 550 W suggested PSU.

Q: Which card has better memory bandwidth?

A: The AMD Radeon HD 6950. It has 160.0 GB/s of bandwidth from 2 GB of GDDR5 on a 256-bit bus. The Quadro K620M has 16.02 GB/s from 2 GB of DDR3 on a 64-bit bus — a 10x difference.

Q: Does the Quadro K620M support Vulkan?

A: Yes. The Quadro K620M supports Vulkan 1.4, along with DirectX 12 (11_0) and OpenGL 4.6. The HD 6950 has no Vulkan support and tops out at DirectX 11.2 (11_0) and OpenGL 4.4.

Q: How do these cards compare to their nearest rivals?

A: The HD 6950 is 0.2% behind the AMD FirePro W600 (6223) and 1.1% behind the NVIDIA Quadro K620 (6282). The Quadro K620M is essentially tied with the AMD Radeon HD 8730M (5955) and 0.5% ahead of the Intel UHD Graphics 730 (5929).

Q: Which card is physically larger?

A: The AMD Radeon HD 6950. It measures 286 mm in length, 126 mm in height, and 42 mm in width, and takes up a dual-slot footprint. The Quadro K620M is an MXM module with no listed dimensions.

Where Each One Wins

AMD Radeon HD 6950 wins on: OpenCL compute performance — it leads the Quadro K620M by 4.2% in the Geekbench OpenCL test. Raw throughput is also heavily in its favor, with 2.253 TFLOPS FP32 versus 863.2 GFLOPS. Memory bandwidth is a 10x advantage at 160.0 GB/s versus 16.02 GB/s. Pixel fill rate (25.60 GPixel/s versus 8.992 GPixel/s) and texture fill rate (70.40 GTexel/s versus 17.98 GTexel/s) are also decisive wins. It has more shading units (1408 versus 384), more TMUs (88 versus 16), and more ROPs (32 versus 8). The 256-bit memory bus versus the 64-bit bus means the HD 6950 can feed its compute units far more effectively.

NVIDIA Quadro K620M wins on: Power efficiency and form factor. The 30 W TDP versus 200 W is a 6.7x advantage in power draw. The MXM module form factor with no power connectors makes it suitable for portable or compact systems, whereas the HD 6950's dual-slot, 286 mm length, and 2x 6-pin connectors demand a full desktop chassis with substantial PSU headroom. The Quadro also has newer API support, including Vulkan 1.4 and DirectX 12 (11_0), which the HD 6950 lacks. Its 28 nm process is newer than the 40 nm node used by the HD 6950, and its transistor density of 13.2M/mm² is nearly double the HD 6950's 6.8M/mm².

The practical split: For a desktop workstation where power is cheap and space is available, the HD 6950 is the stronger compute performer. For a mobile workstation or a compact chassis where the 200 W TDP and dual-slot footprint are non-starters, the Quadro K620M is the only workable choice — and it still delivers a 5957 OpenCL score, which is competitive with the AMD Radeon HD 8750M (5970) and the NVIDIA Quadro K4000 (5982). The HD 6950's performance advantage narrows to just 1.1% against the NVIDIA Quadro K620 (6282), which suggests that if you're in the NVIDIA ecosystem and need a desktop card, the K620 is a closer match to the HD 6950 than the K620M is.

Specification Differences

| Specification | AMD Radeon HD 6950 | NVIDIA Quadro K620M |

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

| Architecture | TeraScale 3 | Maxwell |

| Chip | Cayman | GM108S |

| Generation | Northern Islands (HD 6900) | Quadro Kepler-M (Kx200M) |

| Process node | 40 nm | 28 nm |

| Transistors | 2,640 million | 1,020 million |

| Die size | 389 mm² | 77 mm² |

| Transistor density | 6.8M / mm² | 13.2M / mm² |

| Base clock | N/A | 1029 MHz |

| Boost clock | N/A | 1124 MHz |

| Memory clock | 1250 MHz (5 Gbps effective) | 1001 MHz (2 Gbps effective) |

| Memory type | GDDR5 | DDR3 |

| Memory bus | 256 bit | 64 bit |

| Memory bandwidth | 160.0 GB/s | 16.02 GB/s |

| Shading units | 1408 | 384 |

| TMUs | 88 | 16 |

| ROPs | 32 | 8 |

| Pixel rate | 25.60 GPixel/s | 8.992 GPixel/s |

| Texture rate | 70.40 GTexel/s | 17.98 GTexel/s |

| FP32 | 2.253 TFLOPS | 863.2 GFLOPS |

| TDP | 200 W | 30 W |

| Slot width | Dual-slot | MXM Module |

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

| Suggested PSU | 550 W | N/A |

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

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

| OpenGL | 4.4 | 4.6 |

| Vulkan | N/A | 1.4 |

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

| Release date | 2010-12-13 | 2015-02-28 |

| Launch MSRP | 299 USD | N/A |