AMD Radeon RX 550X vs NVIDIA Tesla K20c Comparison

The NVIDIA Tesla K20c and AMD Radeon RX 550X represent two distinct eras of GPU design, with the former built as a high-compute workstation part and the latter as a low-power consumer card. The data shows a clear split in their intended use cases, driven by raw compute throughput versus modern API support and efficiency. The Tesla K20c dominates in raw OpenCL performance, while the RX 550X offers a more balanced feature set for contemporary software environments.

Where Each One Wins

The NVIDIA Tesla K20c wins decisively in raw computational throughput, as evidenced by its sole head-to-head benchmark victory. In the Geekbench OpenCL test, it scores 11,479 points against the RX 550X’s 9,662 points, a lead of 18.8%. This advantage stems from its massive execution resources: 2,496 shading units, 208 texture mapping units, and 40 ROPs, paired with a 320-bit memory bus delivering 208.0 GB/s of bandwidth. For applications that scale with parallel FP32 compute, such as scientific simulations or data processing, the K20c’s 3.524 TFLOPS of FP32 performance is the clear winner.

Conversely, the AMD Radeon RX 550X wins in modern system integration and API compatibility. It supports DirectX 12 (12_0), a full step above the K20c’s DirectX 12 (11_0) implementation, and Vulkan 1.3 versus the K20c’s Vulkan 1.2.175. The RX 550X also includes display outputs (1x DVI, 1x HDMI 2.0b, 1x DisplayPort 1.4a), whereas the K20c has no outputs, making the AMD card the only option for any visual output. Its PCIe 3.0 x8 interface is also newer than the K20c’s PCIe 2.0 x16, which may reduce bandwidth bottlenecks in modern systems. The RX 550X also provides native FP16 support at a 1:1 ratio with FP32, a capability the K20c lacks entirely.

The RX 550X further wins on efficiency and physical footprint. Its 50 W TDP is a fraction of the K20c’s 225 W, and it requires no external power connectors, while the K20c needs a 6-pin and an 8-pin connector. The AMD card’s 145 mm length (5.7 inches) is dramatically shorter than the K20c’s 267 mm (10.5 inches), making it suitable for compact systems. The RX 550X also offers a higher transistor density (21.4M / mm² on a 14 nm process) compared to the K20c (12.6M / mm² on 28 nm), indicating a more modern manufacturing approach.

The Verdict

The data points to a clear recommendation based on workload. For pure compute tasks that leverage OpenCL and require maximum FP32 throughput, the NVIDIA Tesla K20c is the superior choice. Its 18.8% lead in the head-to-head benchmark, combined with a 51st percentile ranking versus the RX 550X’s 49th percentile, shows it outperforms its rival in raw number-crunching. The K20c’s 5 GB of memory and 208.0 GB/s bandwidth also provide a larger working set for data-heavy applications.

However, the AMD Radeon RX 550X is the more practical pick for general-purpose use or systems needing display output. Its modern API support (Vulkan 1.3, DirectX 12_0) ensures better compatibility with current games and applications, which often rely on these newer interfaces. The RX 550X’s low power draw and compact size make it far easier to integrate into existing builds, and its FP16 capability opens doors for machine learning inference workloads that the K20c cannot handle. The RX 550X also has a higher average benchmark score when considering all tests: 10,481 points versus the K20c’s 11,479 points (which is based on a single benchmark, while the RX 550X includes both OpenCL and Vulkan results).

Ultimately, the choice hinges on whether the user prioritizes raw compute density or modern feature support. The K20c wins on performance per watt in compute scenarios, but the RX 550X wins on versatility and energy efficiency. Given the K20c’s end-of-life status and lack of outputs, the RX 550X is likely the better recommendation for most users unless they specifically need the K20c’s compute headroom.

Head-to-Head Benchmarks

The only direct comparison available is the Geekbench OpenCL test, where the NVIDIA Tesla K20c decisively outperforms the AMD Radeon RX 550X. The K20c scores 11,479 points, while the RX 550X scores 9,662 points, yielding an 18.8% advantage for the NVIDIA card. This is a substantial margin, indicating that the K20c’s 2,496 shading units and 208 TMUs provide a significant parallel processing advantage over the RX 550X’s 512 shading units and 32 TMUs.

This result aligns with the K20c’s nearest rival comparisons. The K20c is only 0.4% behind the AMD Radeon Pro 5500M and 1.3% behind the AMD Radeon RX 7800 XT, while being 1.9% ahead of the NVIDIA GeForce GTX 780M. In contrast, the RX 550X sits much lower in the rankings, with its closest rivals including the NVIDIA Tesla C2075 (0.8% ahead) and the AMD Radeon RX 6500M (1.2% behind). The performance gap between the two cards is thus consistent with their respective positions in the broader GPU landscape.

Interestingly, the RX 550X shows a different story in its Vulkan benchmark, scoring 11,299 points, which is higher than its OpenCL score of 9,662 points. This suggests that the RX 550X’s architecture is better optimized for Vulkan workloads, potentially closing the gap with the K20c in applications that use this API. However, since the K20c lacks a Vulkan benchmark result, a direct comparison is not possible from the data.

FAQ

Q: Which card has a higher benchmark score?

A: The NVIDIA Tesla K20c has a higher single-benchmark score of 11,479 in Geekbench OpenCL, while the AMD Radeon RX 550X averages 10,481 across its two benchmarks (9,662 in OpenCL and 11,299 in Vulkan).

Q: Does the AMD Radeon RX 550X support newer graphics APIs?

A: Yes, the RX 550X supports DirectX 12 (12_0) and Vulkan 1.3, while the NVIDIA Tesla K20c only supports DirectX 12 (11_0) and Vulkan 1.2.175.

Q: Can either card output video to a display?

A: Only the AMD Radeon RX 550X has display outputs (1x DVI, 1x HDMI 2.0b, 1x DisplayPort 1.4a). The NVIDIA Tesla K20c has no outputs, making it unsuitable for display purposes.

Q: What is the memory configuration difference?

A: The NVIDIA Tesla K20c has 5 GB of GDDR5 memory on a 320-bit bus with 208.0 GB/s bandwidth. The AMD Radeon RX 550X has 4 GB of GDDR5 memory on a 128-bit bus with 96.00 GB/s bandwidth.

Q: How do their power requirements compare?

A: The NVIDIA Tesla K20c has a 225 W TDP and requires a 550 W suggested PSU with 1x 6-pin and 1x 8-pin connectors. The AMD Radeon RX 550X has a 50 W TDP, a 250 W suggested PSU, and requires no external power connectors.

Q: Which card is smaller in physical size?

A: The AMD Radeon RX 550X is 145 mm (5.7 inches) long, while the NVIDIA Tesla K20c is 267 mm (10.5 inches) long, making the RX 550X significantly more compact.

Architecture Differences

The NVIDIA Tesla K20c is built on the GK110 chip using the Kepler architecture, manufactured on a 28 nm process at TSMC. It contains 7,080 million transistors on a 561 mm² die, resulting in a transistor density of 12.6M / mm². This design prioritizes raw FP32 compute, with 2,496 shading units, 208 TMUs, and 40 ROPs. The K20c’s memory subsystem includes 5 GB of GDDR5 on a 320-bit bus, providing 208.0 GB/s of bandwidth. It belongs to the Tesla Kepler generation (Kxx) and has a predecessor of Tesla Fermi and a successor of Tesla Maxwell.

The AMD Radeon RX 550X uses the Lexa chip based on the GCN 4.0 architecture, fabricated on a 14 nm process at GlobalFoundries. It packs 2,200 million transistors into a 103 mm² die, achieving a higher transistor density of 21.4M / mm². The RX 550X features 512 shading units, 32 TMUs, and 16 ROPs, with 4 GB of GDDR5 on a 128-bit bus yielding 96.00 GB/s bandwidth. It is part of the Polaris (RX 500X) generation, with Polaris as its predecessor and Vega as its successor. Notably, the RX 550X supports FP16 compute at a 1:1 ratio with FP32, a feature absent from the K20c.

The manufacturing node difference is stark: 28 nm versus 14 nm, giving the RX 550X a clear efficiency advantage. The K20c’s older Kepler architecture lacks modern API features like full DirectX 12 support, while the RX 550X’s GCN 4.0 architecture includes Vulkan 1.3 and DirectX 12_0. The K20c’s compute-focused design also means it has no display outputs, whereas the RX 550X includes three display connectors. These architectural choices reflect their different target markets: the K20c for datacenter compute, the RX 550X for consumer graphics.

Specification Differences

The two cards differ across nearly every major specification. The NVIDIA Tesla K20c has 2,496 shading units, 208 TMUs, and 40 ROPs, while the AMD Radeon RX 550X has 512 shading units, 32 TMUs, and 16 ROPs. The K20c’s memory is 5 GB of GDDR5 on a 320-bit bus with 208.0 GB/s bandwidth, whereas the RX 550X offers 4 GB of GDDR5 on a 128-bit bus with 96.00 GB/s bandwidth. The K20c’s memory clock is 1300 MHz (5.2 Gbps effective), while the RX 550X runs at 1500 MHz (6 Gbps effective).

Clock speeds also differ significantly. The K20c has no listed base or boost clocks, while the RX 550X has a base clock of 1100 MHz and a boost clock of 1183 MHz. Pixel and texture rates reflect the compute gap: the K20c achieves 36.71 GPixel/s and 146.8 GTexel/s, versus the RX 550X’s 18.93 GPixel/s and 37.86 GTexel/s. FP32 performance is 3.524 TFLOPS for the K20c and 1,211.4 GFLOPS for the RX 550X, with the RX 550X also offering 1,211.4 GFLOPS FP16.

Power and physical specs diverge sharply. The K20c has a 225 W TDP, requires 1x 6-pin and 1x 8-pin connectors, and a 550 W suggested PSU. The RX 550X has a 50 W TDP, no power connectors, and a 250 W suggested PSU. Both are dual-slot, but the K20c is 267 mm long versus the RX 550X’s 145 mm. Bus interfaces differ: PCIe 2.0 x16 for the K20c, PCIe 3.0 x8 for the RX 550X. Display outputs are absent on the K20c, while the RX 550X has 1x DVI, 1x HDMI 2.0b, and 1x DisplayPort 1.4a. API support favors the RX 550X with DirectX 12_0 and Vulkan 1.3, against the K20c’s DirectX 11_0 and Vulkan 1.2.175. The K20c launched with an MSRP of 3,199 USD, while the RX 550X has no listed launch MSRP.