AMD Radeon RX 6600 vs NVIDIA Tesla K20m Comparison

The benchmark database places the NVIDIA Tesla K20m and the AMD Radeon RX 6600 in nearly the same performance tier, with average scores of 19,089 and 19,036 respectively. That is a gap of only 0.3%, placing the Tesla K20m slightly ahead in the aggregate. However, the head-to-head benchmark results tell a different story, showing the Radeon RX 6600 as the clear winner in the two tests where they are directly compared.

Head-to-Head Benchmarks

The data available for direct comparison consists of two Geekbench compute tests, and in both, the AMD Radeon RX 6600 delivers a decisive victory. In the Geekbench OpenCL test, the Radeon RX 6600 scores 28,850 against the Tesla K20m’s 16,241. This represents a delta of -43.7% from the perspective of the Tesla K20m, meaning the AMD card is approximately 77.6% faster in this specific workload. The margin is even more pronounced in the Geekbench Vulkan test, where the Radeon RX 6600 scores 67,623 compared to the Tesla K20m’s 21,936. The delta here is -67.6%, indicating that the AMD card is more than three times faster in Vulkan compute performance.

Despite this dominant performance in the head-to-head tests, the overall average benchmark score for both cards is remarkably similar. The Tesla K20m averages 19,089 across its two recorded benchmarks, while the Radeon RX 6600 averages 19,036 across a much larger suite of eleven tests. This discrepancy suggests that the Tesla K20m’s average is buoyed by its strong showing in the Vulkan test relative to its OpenCL result, whereas the Radeon RX 6600’s average is pulled down by other workloads not shared between the two. For instance, the Radeon RX 6600’s Passmark scores are relatively low, with a DirectX 12 score of 51 and a DirectX 9 score of 197, which likely contribute to its lower overall average. The head-to-head data, therefore, is the more relevant comparison for compute-focused tasks, where the Radeon RX 6600 is clearly superior.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The NVIDIA Tesla K20m has a slightly higher average benchmark score of 19,089, compared to the AMD Radeon RX 6600’s 19,036. The difference is a marginal 0.3%.

Q: How does the Radeon RX 6600 perform in Vulkan compared to the Tesla K20m?

A: In the Geekbench Vulkan test, the AMD Radeon RX 6600 scores 67,623, which is significantly higher than the Tesla K20m’s 21,936. The data shows a delta of -67.6% for the Tesla K20m, indicating the AMD card is roughly three times faster.

Q: Is the Tesla K20m more powerful in OpenCL compute?

A: No. The data shows the opposite. In the Geekbench OpenCL test, the Radeon RX 6600 scores 28,850 while the Tesla K20m scores 16,241, a delta of -43.7% for the Tesla K20m.

Q: What is the difference in their percentile rankings?

A: The Tesla K20m is in the 64th percentile of all GPUs, while the Radeon RX 6600 is in the 63rd percentile. This places them in essentially the same performance tier overall.

Q: Which GPU has more shading units?

A: The NVIDIA Tesla K20m has 2,496 shading units, while the AMD Radeon RX 6600 has 1,792. Despite having fewer shading units, the Radeon RX 6600 achieves higher compute scores in the head-to-head tests.

Q: What is the Radeon RX 6600’s score in the Passmark G3D test?

A: The AMD Radeon RX 6600 scores 15,096 in the Passmark G3D benchmark. This test is not available for the Tesla K20m in the provided data.

Architecture Differences

The two GPUs are built on fundamentally different architectures from different eras. The NVIDIA Tesla K20m uses the Kepler architecture with the GK110 chip, manufactured on a 28 nm process at TSMC. This is a large chip, with a die size of 561 mm² and a transistor count of 7,080 million. In contrast, the AMD Radeon RX 6600 is based on the RDNA 2.0 architecture with the Navi 23 chip, also built by TSMC but on a much more advanced 7 nm process. This allows the Navi 23 to pack 11,060 million transistors into a die size of just 237 mm². The transistor density tells the story clearly: the RDNA 2.0 chip has 46.7 million transistors per square millimeter, versus 12.6 million for the Kepler chip.

The memory subsystems also differ significantly. The Tesla K20m uses 5 GB of GDDR5 memory on a 320-bit bus, yielding a bandwidth of 208.0 GB/s. The Radeon RX 6600 uses 8 GB of GDDR6 memory on a narrower 128-bit bus, but achieves a slightly higher bandwidth of 224.0 GB/s thanks to faster memory clocks. In terms of feature set, the Radeon RX 6600 includes 28 ray tracing cores, a feature entirely absent from the Tesla K20m. The AMD card also supports a more modern API set, including DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the Tesla K20m is limited to DirectX 12 (11_0) and Vulkan 1.2.175.

Specification Differences

The two cards differ across nearly every major specification field. The process node is a clear differentiator, with the Tesla K20m on 28 nm and the Radeon RX 6600 on 7 nm. This leads to a massive difference in transistor density, as noted, with the AMD chip achieving 46.7M / mm² versus 12.6M / mm² for the NVIDIA chip. The memory configuration differs in size, type, and bus width: 5 GB of GDDR5 on a 320-bit bus for the Tesla K20m, versus 8 GB of GDDR6 on a 128-bit bus for the Radeon RX 6600. Despite the narrower bus, the Radeon RX 6600 has higher memory bandwidth at 224.0 GB/s compared to 208.0 GB/s.

Compute unit counts also vary. The Tesla K20m has 2,496 shading units, 208 TMUs, and 40 ROPs. The Radeon RX 6600 has fewer shading units (1,792) and TMUs (112), but more ROPs (64). The clock speeds are drastically different, with the Radeon RX 6600 featuring a base clock of 1626 MHz and a boost clock of 2491 MHz, while the Tesla K20m has no base or boost clock listed in the data. Consequently, the pixel rate and texture rate are much higher on the AMD card: 159.4 GPixel/s and 279.0 GTexel/s, respectively, versus 36.71 GPixel/s and 146.8 GTexel/s for the NVIDIA card. The FP32 performance follows suit, with the Radeon RX 6600 delivering 8.928 TFLOPS versus 3.524 TFLOPS for the Tesla K20m.

Power and physical characteristics also differ substantially. The Tesla K20m has a TDP of 225 W and requires both a 6-pin and an 8-pin power connector, with a suggested PSU of 550 W. The Radeon RX 6600 has a much lower TDP of 132 W, needs only a single 8-pin connector, and has a suggested PSU of 300 W. The Tesla K20m is a longer card at 267 mm, while the Radeon RX 6600 is 190 mm long. The bus interface is also different, with the Tesla K20m using PCIe 2.0 x16 and the Radeon RX 6600 using PCIe 4.0 x8. Finally, the Tesla K20m has no display outputs, while the Radeon RX 6600 has 1x HDMI 2.1 and 3x DisplayPort 1.4a.

The Verdict

The data presents a clear choice based on workload. For raw compute performance in the shared benchmarks, the AMD Radeon RX 6600 is the unequivocal winner. It leads by 43.7% in OpenCL and by 67.6% in Vulkan. The Radeon RX 6600 also offers modern features like ray tracing cores, a much smaller physical footprint, lower power consumption, and a newer API set. The Tesla K20m, however, holds a tiny edge in the overall average benchmark score, driven by its 64th percentile ranking versus the Radeon RX 6600’s 63rd. This suggests that in the broader spectrum of all workloads, the Tesla K20m remains competitive, but the head-to-head data indicates it is outclassed in modern compute APIs. For any user focused on the Geekbench compute tests, the Radeon RX 6600 is the superior product.

Where Each One Wins

The AMD Radeon RX 6600 wins in every head-to-head benchmark available. It excels in both OpenCL and Vulkan compute tests, with the Vulkan advantage being particularly substantial. The data shows the Radeon RX 6600 also wins on memory bandwidth (224.0 GB/s vs 208.0 GB/s), FP32 throughput (8.928 TFLOPS vs 3.524 TFLOPS), and pixel/texture rates. It is also the only card of the two with display outputs, making it the clear choice for any task requiring video output.

The NVIDIA Tesla K20m’s wins are more subtle. It has a higher average benchmark score (19,089 vs 19,036) and a slightly better percentile ranking (64th vs 63rd). It also has more shading units (2,496 vs 1,792) and a wider memory bus (320-bit vs 128-bit), which could theoretically benefit certain bandwidth-sensitive workloads that are not captured in the shared head-to-head tests. The Tesla K20m also has a larger die size and more transistors, though this is a reflection of its older, less efficient architecture. For users running legacy compute workloads that rely on CUDA or specific Kepler optimizations, the Tesla K20m may hold an advantage, but the provided benchmark data does not show any test where it beats the Radeon RX 6600.