NVIDIA Tesla K20m vs NVIDIA Tesla K80 Comparison

The benchmark data divides these two Tesla accelerators cleanly: the NVIDIA Tesla K80 wins the OpenCL compute test by a substantial margin, while the older NVIDIA Tesla K20m takes the Vulkan test decisively. Overall, the K80 posts a higher average benchmark score (18,866 vs. 19,089 for the K20m), but the K20m actually edges ahead in average score despite losing one of the two head-to-head tests—a nuance driven by the K20m’s strong Vulkan performance. Both cards are end-of-life products from the same Tesla Kepler generation, yet they target different compute profiles.

Head-to-Head Benchmarks

The most significant performance gap appears in the Geekbench OpenCL test, where the NVIDIA Tesla K80 delivers a score of 18,620 against the K20m’s 16,241. That is a 12.8% advantage for the K80, a decisive lead in raw compute throughput. The K80’s OpenCL result also places it within 0.4% of the NVIDIA GeForce RTX 2070 (18,789), while the K20m’s 16,241 sits roughly 3.7% below the same rival. In this test, the K80’s higher FP32 rating (4.113 TFLOPS vs. 3.524 TFLOPS) and larger memory subsystem (12 GB GDDR5 on a 384-bit bus vs. 5 GB on a 320-bit bus) translate directly into a measurable win.

The Vulkan test flips the script. Here, the NVIDIA Tesla K20m scores 21,936, a 14.8% advantage over the K80’s 19,111. This is a substantial reversal—the K20m’s Vulkan score is 15% higher than its own OpenCL result, while the K80’s Vulkan score actually drops 2.6% relative to its OpenCL performance. Interestingly, the K20m’s Vulkan score of 21,936 places it well above all its nearest rivals listed: it beats the NVIDIA GeForce GTX 780 (19,164, a -0.4% delta) by roughly 14.5%, and the NVIDIA Quadro K6000 (19,030) by about 15.3%. The K80’s Vulkan score of 19,111, by contrast, is essentially flat against its nearest rivals—it trails the NVIDIA RTX 2000 Ada Generation (18,954) by 0.8% and the Quadro K6000 (19,030) by 0.4%.

The win count is even: one benchmark win each. But the margins tell a different story. The K80’s OpenCL win is 12.8%, while the K20m’s Vulkan win is 14.8%. The K20m’s victory is slightly larger in percentage terms, yet the K80’s OpenCL lead is more relevant for typical compute workloads. The average benchmark scores reflect this tension: the K20m averages 19,089 (64th percentile among all GPUs), while the K80 averages 18,866 (63rd percentile). That 1.2% average difference is well within the noise of the nearest rivals—the K20m’s closest competitor, the NVIDIA GeForce RTX 4050 Mobile, sits at 19,049 (a 0.2% delta), while the K80’s nearest rival, the NVIDIA RTX 2000 Ada Generation, is 0.5% higher.

Where Each One Wins

The NVIDIA Tesla K80 is the clear choice for OpenCL-centric compute workloads. Its 12.8% lead in that benchmark is backed by hardware that scales for throughput: 4.113 TFLOPS FP32 performance, 171.4 GTexel/s texture rate, and 42.85 GPixel/s pixel rate. The K80 also carries 12 GB of GDDR5 memory with 240.6 GB/s bandwidth, which is 7 GB more capacity and 15.7% more bandwidth than the K20m. For tasks that saturate memory or rely on sustained FP32 compute, the data points squarely to the K80.

The NVIDIA Tesla K20m wins decisively in Vulkan. Its 14.8% margin over the K80 is the single largest gap in the head-to-head data, and its Vulkan score (21,936) is 35% higher than its own OpenCL result. This suggests the K20m’s driver or hardware pipeline is better suited to Vulkan’s API model, despite having lower raw specs. The K20m’s 3.524 TFLOPS FP32 and 208.0 GB/s bandwidth are both lower than the K80’s, yet it still outperforms in this specific test. Notably, the K20m’s Vulkan score is 14.5% above its nearest rival (the GTX 780), while the K80’s Vulkan score is essentially tied with its nearest rivals—the largest delta being -0.9% against the Quadro K6000.

For average performance across both tests, the K20m edges ahead with a 19,089 average vs. 18,866 for the K80. But that 1.2% difference is less meaningful than the per-test splits. The K20m also holds a slightly higher percentile ranking (64th vs. 63rd), though both cards sit in the lower-middle of the GPU performance distribution.

The Verdict

Choose the NVIDIA Tesla K80 if your workloads are OpenCL-bound. The data is unambiguous: 12.8% faster in OpenCL, with 2.4x the memory capacity and 15.7% more bandwidth. The K80’s 4.113 TFLOPS FP32 and 171.4 GTexel/s texture rate outclass the K20m’s 3.524 TFLOPS and 146.8 GTexel/s, and it posts a higher pixel rate (42.85 vs. 36.71 GPixel/s). For compute density, the K80 also packs 7,100 million transistors on the same 561 mm² die as the K20m, yielding a slightly higher transistor density (12.7M/mm² vs. 12.6M/mm²).

Choose the NVIDIA Tesla K20m if Vulkan performance is the priority. The 14.8% win in that test is the largest head-to-head margin, and the K20m’s Vulkan score (21,936) is 15.3% above its nearest named rival (the Quadro K6000). The K20m also carries a higher average benchmark score (19,089 vs. 18,866) and a better percentile rank (64th vs. 63rd). Its lower TDP (225 W vs. 300 W) and simpler power requirement (1x 6-pin + 1x 8-pin vs. 1x 8-pin) make it less demanding on system power, though the suggested PSU is still 550 W.

For most users, the K80 is the safer pick due to its OpenCL dominance and memory advantage. But the K20m’s Vulkan edge is real and substantial—if that API matters, the K20m is the data-backed choice. Both are end-of-life, so availability and driver maturity may factor in, but the benchmark results favor the K80 for general compute and the K20m for Vulkan-specific tasks.

FAQ

Q: Which card has a higher average benchmark score?

A: The NVIDIA Tesla K20m averages 19,089 across its two benchmarks, while the NVIDIA Tesla K80 averages 18,866. The K20m also ranks higher in percentile (64th vs. 63rd).

Q: What is the biggest performance gap between the two cards?

A: The largest gap is in the Geekbench Vulkan test, where the K20m scores 21,936 against the K80’s 19,111—a 14.8% advantage for the K20m. The second-largest gap is in Geekbench OpenCL, where the K80 leads by 12.8% (18,620 vs. 16,241).

Q: How does the K80 compare to its nearest rivals?

A: The K80’s average score (18,866) is within 0.4% of the NVIDIA GeForce RTX 2070 (18,789) and 0.5% below the NVIDIA RTX 2000 Ada Generation (18,954). It trails the NVIDIA Quadro K6000 (19,030) by 0.9% and the AMD Radeon RX 6600 (19,036) by 0.9%.

Q: How much memory does each card have, and does it affect performance?

A: The K80 has 12 GB of GDDR5 memory on a 384-bit bus with 240.6 GB/s bandwidth. The K20m has 5 GB on a 320-bit bus with 208.0 GB/s. The K80’s larger memory and higher bandwidth likely contribute to its 12.8% OpenCL lead.

Q: Are these cards still in production?

A: No. Both are marked end-of-life. The K20m was released in January 2013, and the K80 in November 2014. Both belong to the Tesla Kepler (Kxx) generation.

Q: Which card has better Vulkan support?

A: The K20m. It scores 21,936 in Geekbench Vulkan versus 19,111 for the K80, a 14.8% margin. Both support Vulkan 1.2.175, but the K20m’s implementation appears more efficient in this benchmark.

Architecture Differences

Both cards are built on TSMC’s 28 nm process with nearly identical die sizes (561 mm²), but they use different chips. The K20m uses the GK110 chip, while the K80 uses the GK210. The K80’s GK210 packs 7,100 million transistors versus 7,080 million for the GK110, a difference of 20 million transistors, yielding a slightly higher transistor density (12.7M/mm² vs. 12.6M/mm²). The K80 is classified as Kepler 2.0 architecture, while the K20m is plain Kepler—a generational refinement rather than a full redesign.

The shading unit count is identical: 2,496 on both cards, with 208 texture mapping units each. The key architectural difference lies in the ROP count: the K80 has 48 ROPs versus 40 on the K20m, a 20% increase that explains its higher pixel rate (42.85 GPixel/s vs. 36.71 GPixel/s). The K80 also runs with explicit base and boost clocks (562 MHz base, 824 MHz boost), while the K20m’s clocks are not specified in the data—only its memory clock of 1300 MHz (5.2 Gbps effective) versus the K80’s 1253 MHz (5 Gbps effective).

The K80 supports DirectX 12 (11_1), while the K20m is limited to DirectX 12 (11_0). Both support OpenGL 4.6 and Vulkan 1.2.175. Neither card has display outputs, indicating their dedicated compute role. The K80 uses a PCIe 3.0 x16 interface, while the K20m is limited to PCIe 2.0 x16—a generational difference that affects host transfer speeds. Both are dual-slot cards with identical dimensions (267 mm / 10.5 inches length).

Specification Differences

The two cards diverge most sharply on memory and power. The K80 offers 12 GB of GDDR5 on a 384-bit bus, versus 5 GB on a 320-bit bus for the K20m—a 140% capacity increase and a 64-bit wider bus. Bandwidth follows: 240.6 GB/s for the K80 versus 208.0 GB/s for the K20m, a 15.7% advantage. The K80’s FP32 performance is 4.113 TFLOPS versus 3.524 TFLOPS for the K20m, a 16.7% lead. Its texture rate (171.4 GTexel/s) and pixel rate (42.85 GPixel/s) also outpace the K20m’s 146.8 GTexel/s and 36.71 GPixel/s.

Power consumption scales accordingly: the K80 draws 300 W TDP versus 225 W for the K20m, and suggests a 700 W PSU versus 550 W. The K80 uses a single 8-pin power connector, while the K20m requires 1x 6-pin + 1x 8-pin. The K80 runs at explicit base/boost clocks (562/824 MHz) with memory at 1253 MHz (5 Gbps effective), while the K20m’s core clocks are unspecified, with memory at 1300 MHz (5.2 Gbps effective)—the K20m’s memory clock is actually 3.8% higher.

The K80 supports PCIe 3.0 x16, while the K20m is limited to PCIe 2.0 x16. DirectX support differs: the K80 supports 12 (11_1), the K20m 12 (11_0). Both use a dual-slot form factor, measure 267 mm in length, have no display outputs, and are end-of-life. The K20m has a launch MSRP of 3,199 USD; no launch MSRP is listed for the K80. Both cards share the same 28 nm process, TSMC foundry, and 561 mm² die size, with the K80’s transistor count (7,100M) only slightly above the K20m’s (7,080M).