GPU Comparison

The NVIDIA Quadro K620 and AMD Radeon HD 6950 are two end-of-life graphics cards from different eras, targeting different segments. The data shows they land in the same performance percentile overall, yet their architectural approaches and benchmark results reveal distinct characteristics. This analysis compares them head-to-head using only the provided benchmark data and specifications.

Head-to-Head Benchmarks

The only direct benchmark comparison available is Geekbench OpenCL, where the NVIDIA Quadro K620 scores 6693 against the AMD Radeon HD 6950’s 6210. That gives the Quadro K620 a 7.8% lead in this single test. This is a meaningful margin, though not a dominant one; it places the K620 clearly ahead in compute workloads as measured by OpenCL.

Looking at the broader average benchmark scores, the Quadro K620 averages 6282 across its two recorded tests (OpenCL and Vulkan), while the Radeon HD 6950 averages 6210 from its single OpenCL result. The delta here is roughly 1.2% in favor of the K620, which is within the noise of typical benchmark variance. Both cards sit at the 36th percentile among all GPUs, meaning they occupy the same tier of overall performance relative to the entire GPU landscape.

The nearest rivals for the K620 include the NVIDIA GeForce RTX 5070 Ti SUPER at 6270 (0.2% behind the K620) and the AMD Radeon R7 M350 at 6327 (0.7% ahead). For the HD 6950, the closest competitor is the AMD FirePro W600 at 6223 (0.2% behind), with the RTX 4070 Ti SUPER AD102 at 6270 (0.9% ahead). The fact that both cards are bracketed by modern high-end GPUs like the RTX 5070 Ti SUPER and RTX 4070 Ti SUPER in their rival lists shows that their average scores land in a peculiar middle ground, they are not competing with those cards in real-world performance, but their benchmark averages happen to align closely.

The K620’s Geekbench Vulkan score of 5870 is worth noting, as the HD 6950 has no Vulkan support at all. This means the K620 can run a broader range of modern compute workloads, while the HD 6950 is limited to older APIs like DirectX 11.2 and OpenGL 4.4. In the one directly comparable test, the K620 wins decisively by 7.8%, and its additional Vulkan capability gives it a functional advantage that raw scores do not fully capture.

Where Each One Wins

The NVIDIA Quadro K620 wins in compute performance as measured by OpenCL, with a 7.8% higher score than the Radeon HD 6950. It also wins in API support, offering Vulkan 1.4 and DirectX 12 (11_0), whereas the HD 6950 lacks Vulkan entirely and supports only DirectX 11.2 (11_0). For users running modern compute frameworks or applications that leverage Vulkan, the K620 is the only viable option between the two.

The AMD Radeon HD 6950 wins in raw memory bandwidth and pixel throughput. Its memory subsystem delivers 160.0 GB/s across a 256-bit bus, compared to the K620’s 28.80 GB/s over a 128-bit bus, a 5.5x advantage in bandwidth. Its pixel rate is 25.60 GPixel/s versus the K620’s 17.98 GPixel/s, a 42% lead. Texture rate also favors the HD 6950 at 70.40 GTexel/s versus 26.98 GTexel/s, a 2.6x advantage. These figures suggest the HD 6950 would handle fill-rate-bound workloads, such as high-resolution texture mapping or multi-sample anti-aliasing, more effectively than the K620.

In terms of raw compute throughput, the HD 6950’s FP32 rating of 2.253 TFLOPS dwarfs the K620’s 863.2 GFLOPS. Yet the OpenCL benchmark tells the opposite story, with the K620 scoring higher. This discrepancy indicates that the HD 6950’s theoretical peak does not translate into practical compute efficiency, likely due to architectural differences in how work is scheduled and executed.

FAQ

Q: Which card has a higher average benchmark score?

A: The NVIDIA Quadro K620 averages 6282 across its two recorded benchmarks (OpenCL and Vulkan), while the AMD Radeon HD 6950 averages 6210 from its single OpenCL result. The K620 leads by approximately 1.2%.

Q: Does the AMD Radeon HD 6950 support Vulkan?

A: No. The HD 6950 lists no Vulkan support in its API specifications, whereas the Quadro K620 supports Vulkan 1.4.

Q: How much faster is the K620 in OpenCL?

A: The K620 scores 6693 in Geekbench OpenCL against the HD 6950’s 6210, a 7.8% advantage for the K620.

Q: Which card has higher memory bandwidth?

A: The AMD Radeon HD 6950 has 160.0 GB/s of bandwidth over a 256-bit bus, compared to the Quadro K620’s 28.80 GB/s over a 128-bit bus.

Q: What is the transistor density of each card?

A: The K620 packs 1,870 million transistors into a 148 mm² die for a density of 12.6M per mm², while the HD 6950 has 2,640 million transistors on a 389 mm² die, yielding 6.8M per mm².

Q: Which card consumes less power?

A: The Quadro K620 has a TDP of 45 W with no power connectors and a suggested PSU of 200 W. The Radeon HD 6950 has a TDP of 200 W, requires two 6-pin power connectors, and suggests a 550 W PSU.

Specification Differences

The two cards differ across nearly every major specification. The Quadro K620 uses 2 GB of DDR3 memory on a 128-bit bus, delivering 28.80 GB/s. The Radeon HD 6950 uses 2 GB of GDDR5 on a 256-bit bus, delivering 160.0 GB/s. Clock speeds differ: the K620 runs at 1058 MHz base and 1124 MHz boost, while the HD 6950 has no base or boost clock listed, only a memory clock of 1250 MHz (5 Gbps effective).

The K620 has 384 shading units, 24 TMUs, and 16 ROPs. The HD 6950 has 1408 shading units, 88 TMUs, and 32 ROPs, roughly 3.7x, 3.7x, and 2x more, respectively. Pixel rate is 17.98 GPixel/s for the K620 versus 25.60 GPixel/s for the HD 6950. Texture rate is 26.98 GTexel/s versus 70.40 GTexel/s. FP32 compute is 863.2 GFLOPS versus 2.253 TFLOPS.

Power and physical specs diverge sharply. The K620 draws 45 W, is single-slot, requires no power connectors, and suggests a 200 W PSU. It measures 160 mm in length and 69 mm in height. The HD 6950 draws 200 W, is dual-slot, requires two 6-pin connectors, and suggests a 550 W PSU. It measures 286 mm in length, 126 mm in height, and 42 mm in width. Display outputs also differ: the K620 has one DVI and one DisplayPort 1.2, while the HD 6950 has two DVI, one HDMI 1.4a, and two mini-DisplayPort 1.2.

Architecture Differences

The NVIDIA Quadro K620 is built on the GM107 chip using Maxwell architecture, fabricated on a 28 nm process at TSMC with 1,870 million transistors on a 148 mm² die. Its transistor density is 12.6M per mm². The AMD Radeon HD 6950 uses the Cayman chip with TeraScale 3 architecture, fabricated on a 40 nm process at TSMC with 2,640 million transistors on a 389 mm² die. Its transistor density is 6.8M per mm². The K620’s newer, denser process node allows it to achieve higher efficiency despite fewer transistors.

The K620 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. This makes the K620 compatible with modern compute APIs that the HD 6950 cannot use. The K620’s memory clock is 900 MHz (1800 Mbps effective), while the HD 6950’s memory clock is 1250 MHz (5 Gbps effective). The HD 6950’s memory type is GDDR5, which explains its significantly higher bandwidth despite the older process.

The K620’s generation is listed as Quadro Kepler (Kx200), though its architecture is Maxwell, indicating a transitional naming scheme. The HD 6950 belongs to the Northern Islands (HD 6900) generation. Release dates reflect their eras: the K620 launched in July 2014, while the HD 6950 launched in December 2010, a gap of roughly three and a half years.

The Verdict

The data points to a clear split. For users running modern compute workloads, the NVIDIA Quadro K620 is the better choice. It wins the only direct benchmark by 7.8%, supports Vulkan and DirectX 12, and does so at a fraction of the power draw: 45 W versus 200 W. Its single-slot design, lack of power connectors, and 200 W suggested PSU make it far easier to integrate into existing systems. The K620’s higher transistor density (12.6M per mm² versus 6.8M) reflects a more efficient design.

For users prioritizing raw fill-rate or memory bandwidth, the AMD Radeon HD 6950 has clear advantages. Its 160.0 GB/s bandwidth, 25.60 GPixel/s pixel rate, and 70.40 GTexel/s texture rate dwarf the K620’s corresponding figures. Its 2.253 TFLOPS FP32 rating also suggests higher theoretical compute, though the OpenCL benchmark contradicts this in practice.

The HD 6950’s 2x ROP count (32 versus 16) and 3.7x TMU count (88 versus 24) indicate it was designed for high-resolution rasterization workloads. Its 256-bit bus and GDDR5 memory are hallmarks of a performance-oriented part. However, its lack of Vulkan support and older API set limit its relevance in modern software environments. The K620, despite lower raw specs, delivers better real-world compute performance in the benchmark that matters most, and its API support ensures it can run a wider range of current applications.

The choice comes down to workload. The K620 is the sensible pick for compute-focused tasks, low-power builds, or systems needing modern API support. The HD 6950 makes sense only for legacy applications that exploit its bandwidth and fill-rate advantages, where its high power draw and dual-slot footprint are acceptable. Benchmark results indicate the K620 is the more balanced and future-proof option, with the HD 6950 holding specific niches that the K620 cannot fill.