AMD Radeon HD 8950M vs NVIDIA Tesla K20c Comparison

Head-to-Head Benchmarks

The only recorded head-to-head benchmark between these two parts is Geekbench OpenCL, and the result is a decisive win for the AMD Radeon HD 8950M. The AMD part scores 13,772 points, while the NVIDIA Tesla K20c manages 11,479 points. That is a 20% advantage for the AMD Radeon HD 8950M, and it represents the sole comparison in the database where both cards ran the identical test.

Looking at the average benchmark scores across all recorded workloads, the AMD Radeon HD 8950M posts 13,376 points, which places it in the 54th percentile of all GPUs. The NVIDIA Tesla K20c, by contrast, has an average score of 11,479 points and sits in the 51st percentile. The gap in raw average performance is roughly 1,900 points, and the percentile difference, while modest, still favors the mobile AMD part.

The nearest rivals for each card put these numbers in context. The AMD Radeon HD 8950M sits within a tight cluster: the AMD Radeon Pro 555 is 0.2% ahead, the AMD Radeon RX 5500M is 0.2% behind, the AMD FirePro M6100 is 0.2% behind, and the AMD Radeon Pro 555X is 0.4% ahead. Essentially, the HD 8950M trades blows with a group of midrange mobile and workstation parts, and its 20% lead over the Tesla K20c is far larger than any of those rival deltas.

The NVIDIA Tesla K20c, on the other hand, is positioned near a different set of competitors. The AMD Radeon Pro 5500M is 0.4% ahead, the AMD Radeon RX 7800 XT is 1.3% ahead, and the NVIDIA GeForce GTX 1660 is 1.7% ahead. The only rival that the Tesla K20c beats is the NVIDIA GeForce GTX 780M, which trails by 1.9%. This indicates that the Tesla K20c, despite its much larger silicon and compute resources, lands in a performance tier that modern midrange parts have long since passed.

It is also notably the AMD Radeon HD 8950M has a secondary benchmark result in Geekbench Vulkan, scoring 12,979 points. No comparable Vulkan result exists for the Tesla K20c in the database, so the OpenCL result remains the only direct point of comparison.

The Verdict

The data is unambiguous: the AMD Radeon HD 8950M wins the sole head-to-head benchmark by 20%, and it also holds a higher average score across the database (13,376 versus 11,479). For any workload that relies on OpenCL compute performance, the AMD part is the stronger choice based on recorded measurements.

The NVIDIA Tesla K20c is not without justification, however. It carries substantially more memory bandwidth and raw shading resources, but the benchmark results show that those resources do not translate into a higher OpenCL score. The Tesla K20c does have a 5 GB frame buffer versus 2 GB, and it offers a 320-bit memory bus versus 128-bit, but the actual measured performance tells a different story.

The percentile rankings reinforce the same conclusion. The AMD part sits at the 54th percentile of all GPUs, while the Tesla K20c sits at the 51st percentile. Neither card is a top-tier performer by modern standards, but the AMD Radeon HD 8950M is clearly the one that delivers better results in the tests recorded here.

For a buyer choosing strictly on benchmark data, the AMD Radeon HD 8950M is the pick. It wins the only direct comparison, it has a higher average score, and it does so with a far lower power draw. The Tesla K20c, with its 225 W TDP and dual-slot form factor, is a workstation-oriented card that appears to have been optimized for other workloads or for compute tasks that are not captured by the OpenCL test in the database. But on the evidence available, the AMD mobile part outperforms it.

Architecture Differences

The two GPUs come from completely different architectural lineages. The AMD Radeon HD 8950M uses the GCN 2.0 architecture, built around the Saturn chip. The NVIDIA Tesla K20c uses the Kepler architecture, built around the GK110 chip. Both are fabricated on a 28 nm process at TSMC, but the similarities end there.

The transistor counts differ dramatically. The AMD chip packs 2,080 million transistors on a die size of 160 mm², which yields a transistor density of 13.0 million transistors per square millimeter. The NVIDIA chip, by contrast, packs 7,080 million transistors on a much larger die of 561 mm², resulting in a slightly lower density of 12.6 million transistors per square millimeter. The Tesla K20c is a much bigger piece of silicon, but it is also older and less dense.

The shading resources are heavily skewed toward the NVIDIA part. The Tesla K20c has 2,496 shading units, 208 texture mapping units, and 40 ROPs. The AMD Radeon HD 8950M has 768 shading units, 48 TMUs, and 16 ROPs. In terms of raw throughput, the NVIDIA card posts 3.524 TFLOPS of FP32 compute, while the AMD card manages 1.651 TFLOPS. The texture rate also favors NVIDIA heavily: 146.8 GTexel/s versus 51.60 GTexel/s. The pixel rate is 36.71 GPixel/s for the Tesla K20c and 17.20 GPixel/s for the AMD part.

Despite this massive theoretical advantage, the Tesla K20c loses the OpenCL benchmark. This suggests that the Kepler architecture, at least in this configuration, does not extract its full compute potential in the Geekbench OpenCL workload, or that the driver and software stack for the AMD GCN 2.0 part is better optimized for this specific test.

Both cards support DirectX 12, but the AMD part supports the 12_0 feature level while the NVIDIA part supports only 11_0. OpenGL support is identical at 4.6, and Vulkan support is close: the AMD card lists version 1.2.170, while the NVIDIA card lists version 1.2.175.

Specification Differences

The memory subsystems are starkly different. The AMD Radeon HD 8950M has 2 GB of GDDR5 on a 128-bit bus, delivering 88.00 GB/s of bandwidth. The NVIDIA Tesla K20c has 5 GB of GDDR5 on a 320-bit bus, delivering 208.0 GB/s of bandwidth. That is more than double the bandwidth and more than double the capacity, but it does not translate into a benchmark win.

The memory clocks also differ. The AMD card runs its memory at 1375 MHz, which translates to 5.5 Gbps effective. The NVIDIA card runs at 1300 MHz, or 5.2 Gbps effective. The wider bus on the NVIDIA card more than compensates for the slightly lower clock.

The power profiles are a major point of separation. The AMD Radeon HD 8950M has a TDP of 100 W and uses an MXM Module slot width, which is designed for laptops and portable systems. The NVIDIA Tesla K20c has a TDP of 225 W, uses a dual-slot form factor, and requires both a 6-pin and an 8-pin power connector. The suggested power supply for the Tesla K20c is 550 W. The AMD card does not list a power connector or suggested PSU, as it is intended for a portable device where power delivery is handled by the system.

The bus interfaces also differ. The AMD card uses PCIe 3.0 x16, while the NVIDIA card uses PCIe 2.0 x16. Display outputs are another clear distinction: the AMD card is listed as "Portable Device Dependent," meaning it relies on the host laptop for display output, while the NVIDIA Tesla K20c has no display outputs at all, as it is a compute-only accelerator.

Physical dimensions are partially listed. The NVIDIA Tesla K20c has a length of 267 mm (10.5 inches), while the AMD card does not list a length due to its MXM form factor.

The release dates are close: the AMD Radeon HD 8950M was released on May 13, 2013, and the NVIDIA Tesla K20c was released on November 11, 2012. Both are end-of-life products. The AMD card has a predecessor named London and a successor named Gem System, while the NVIDIA card has a predecessor named Tesla Fermi and a successor named Tesla Maxwell. The Tesla K20c has a recorded launch MSRP of 3,199 USD.

FAQ

Q: Which GPU wins the only direct benchmark comparison?

A: The AMD Radeon HD 8950M wins the Geekbench OpenCL test with a score of 13,772 against the NVIDIA Tesla K20c's 11,479, a 20% advantage.

Q: How do the average benchmark scores compare?

A: The AMD Radeon HD 8950M has an average score of 13,376, while the NVIDIA Tesla K20c has an average score of 11,479. The AMD card also holds a higher percentile rank at 54 versus 51.

Q: What are the memory specifications for each card?

A: The AMD Radeon HD 8950M has 2 GB of GDDR5 on a 128-bit bus with 88.00 GB/s bandwidth. The NVIDIA Tesla K20c has 5 GB of GDDR5 on a 320-bit bus with 208.0 GB/s bandwidth.

Q: Which card has more shading units and compute throughput?

A: The NVIDIA Tesla K20c has 2,496 shading units and 3.524 TFLOPS of FP32 compute, while the AMD Radeon HD 8950M has 768 shading units and 1.651 TFLOPS.

Q: What are the power consumption figures?

A: The AMD Radeon HD 8950M has a TDP of 100 W, while the NVIDIA Tesla K20c has a TDP of 225 W and requires a 550 W power supply.

Q: Do both cards support the same APIs?

A: Both support OpenGL 4.6 and Vulkan, though the NVIDIA card lists Vulkan 1.2.175 versus AMD's 1.2.170. For DirectX, the AMD card supports version 12 with the 12_0 feature level, while the NVIDIA card supports DirectX 12 with the 11_0 feature level.