NVIDIA GeForce GTX 1080 vs NVIDIA Tesla K20Xm Comparison

The NVIDIA Tesla K20Xm and NVIDIA GeForce GTX 1080 represent two very different eras of GPU design, from the compute-focused Kepler architecture to the efficiency-driven Pascal architecture. While the K20Xm was built for scientific workloads with massive FP32 throughput, the GTX 1080 was designed to dominate gaming and consumer applications. The benchmark data shows a clear generational leap, with the GTX 1080 delivering dramatically higher scores across all shared tests, despite the K20Xm's larger die and higher transistor count. The following analysis breaks down the architectural, benchmark, and specification differences between these two end-of-life cards.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The NVIDIA Tesla K20Xm has a higher average benchmark score of 12,625, while the NVIDIA GeForce GTX 1080 scores 11,960. However, this average is skewed by the limited number of benchmark tests available for the K20Xm, which only has two Geekbench entries.

Q: How does the GTX 1080 compare to its nearest rival in terms of performance?

A: The GTX 1080's average score of 11,960 places it 2.4% ahead of the NVIDIA GeForce GTX 1660 and 1% ahead of the AMD Radeon RX 6500 XT, but it trails the NVIDIA GeForce GTX 960A by 0.3%.

Q: What is the biggest performance gap in the head-to-head benchmarks?

A: The largest gap is in the Geekbench OpenCL test, where the GTX 1080 scores 51,204 compared to the K20Xm's 17,215, representing a 66.4% advantage for the GTX 1080.

Q: Does the Tesla K20Xm support any modern API features?

A: The K20Xm supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175. The GTX 1080 supports a more complete DirectX 12 (12_1) and a newer Vulkan 1.4 specification.

Q: Which card has a higher pixel fill rate?

A: The GTX 1080 has a pixel rate of 110.9 GPixel/s, which is significantly higher than the K20Xm's 40.99 GPixel/s, indicating much faster rasterization capabilities.

Q: What are the launch MSRPs of these two cards?

A: The Tesla K20Xm had a launch MSRP of 7,699 USD, while the GeForce GTX 1080 had a launch MSRP of 599 USD.

Architecture Differences

The K20Xm is built on the GK110 chip using the Kepler architecture, fabricated on a 28 nm process at TSMC. This resulted in a massive 561 mm² die containing 7,080 million transistors, yielding a transistor density of 12.6M per mm². In contrast, the GTX 1080 uses the GP104 chip with the Pascal architecture, built on a 16 nm process, also at TSMC. The smaller 314 mm² die holds 7,200 million transistors, achieving a much higher density of 22.9M per mm². The move to a smaller process node allowed NVIDIA to pack nearly the same transistor count into roughly half the silicon area.

The K20Xm features 2,688 shading units, 224 texture mapping units, and 48 ROPs. The GTX 1080 has 2,560 shading units, 160 TMUs, and 64 ROPs. While the K20Xm has more shaders and TMUs, the GTX 1080 compensates with significantly higher clock speeds. The K20Xm's memory operates at 1300 MHz (5.2 Gbps effective) on a 384-bit bus, providing 249.6 GB/s of bandwidth. The GTX 1080 uses faster GDDR5X memory at 1251 MHz (10 Gbps effective) on a 256-bit bus, delivering 320.3 GB/s of bandwidth. The GTX 1080 also supports FP16 at 138.6 GFLOPS, while the K20Xm has no FP16 capability listed. Both cards use a PCIe 3.0 x16 interface and are dual-slot designs.

Head-to-Head Benchmarks

The head-to-head data is limited to two Geekbench tests, but the results are decisive. In Geekbench Metal, the GTX 1080 scores 23,824 against the K20Xm's 8,035, a 66.3% advantage. This represents a near-tripling of raw compute performance in a graphics API context. The Geekbench OpenCL test shows a similar story, with the GTX 1080 scoring 51,204 versus 17,215 for the K20Xm, a 66.4% gap. The K20Xm's 3.935 TFLOPS of FP32 performance is dwarfed by the GTX 1080's 8.873 TFLOPS, which explains the benchmark dominance.

The GTX 1080 wins both head-to-head tests, giving it a 2-0 record. The K20Xm's peak performance is closer to the GTX 1080's nearest rivals. The GTX 1080's average score of 11,960 is 2.4% higher than the GTX 1660, while the K20Xm's average of 12,625 puts it 1.6% behind the AMD Radeon Pro 455. This relative positioning shows that while the GTX 1080 is a clear winner in direct comparison, neither card dominates its respective peer group by a wide margin.

Specification Differences

The two cards differ in nearly every measurable specification. The K20Xm uses a 384-bit memory bus with 6 GB of GDDR5, while the GTX 1080 uses a 256-bit bus with 8 GB of GDDR5X. The memory bandwidth favors the GTX 1080 at 320.3 GB/s versus 249.6 GB/s. The K20Xm has a higher transistor count in terms of raw numbers (7,080 million vs 7,200 million), but the GTX 1080 achieves this in a much smaller die (314 mm² vs 561 mm²). The process node is a major differentiator: 28 nm for the K20Xm and 16 nm for the GTX 1080.

Power consumption is another key difference. The K20Xm draws 235 W and requires a 550 W suggested PSU, while the GTX 1080 uses only 180 W with a 450 W suggested PSU. The GTX 1080 has a single 8-pin power connector, whereas the K20Xm has no power connector specified. The GTX 1080 provides display outputs (1x DVI, 1x HDMI 2.0, 3x DisplayPort 1.4a), while the K20Xm has no outputs at all, reflecting its compute-only design. Clock speeds are starkly different, with the GTX 1080 running at 1607 MHz base and 1733 MHz boost, while the K20Xm has no base or boost clocks listed. The K20Xm's 40.99 GPixel/s pixel rate and 164.0 GTexel/s texture rate are far lower than the GTX 1080's 110.9 GPixel/s and 277.3 GTexel/s.

Where Each One Wins

The GTX 1080 wins in every benchmark category where both cards were tested. In Geekbench Metal, it achieves 23,824 versus the K20Xm's 8,035. In Geekbench OpenCL, it scores 51,204 versus 17,215. The GTX 1080 also has a higher pixel rate (110.9 GPixel/s) and texture rate (277.3 GTexel/s), making it better suited for rasterization-heavy workloads like gaming. Its higher FP32 throughput of 8.873 TFLOPS and faster memory bandwidth of 320.3 GB/s give it a clear edge in general-purpose compute.

The K20Xm's advantages are more structural than performance-based. It has more shading units (2,688 vs 2,560) and more TMUs (224 vs 160), which could theoretically benefit certain compute workloads if clock speeds were equal. However, the data shows no benchmark where this translates into a win. The K20Xm also has a higher average benchmark score than the GTX 1080 (12,625 vs 11,960), though this is based on only two tests. The K20Xm's 48 ROPs are fewer than the GTX 1080's 64, but its larger 384-bit memory bus could be useful for workloads that require high memory addressability rather than raw bandwidth.

The Verdict

The data is unambiguous: the NVIDIA GeForce GTX 1080 is the superior card for virtually any use case. It wins both head-to-head benchmarks by margins exceeding 66%, delivers more than double the FP32 compute performance (8.873 TFLOPS vs 3.935 TFLOPS), and does so while consuming 55 W less power. The GTX 1080's 8 GB of GDDR5X memory with 320.3 GB/s bandwidth provides more capacity and faster throughput than the K20Xm's 6 GB of GDDR5. For gaming, content creation, or general compute, the GTX 1080 is the clear choice.

The Tesla K20Xm should only be considered if you specifically need its unique characteristics: a compute card with no display outputs, 2,688 shading units, and a 384-bit memory bus. Its higher average benchmark score of 12,625 is misleading, as it comes from a smaller test suite. The K20Xm's launch MSRP of 7,699 USD reflects its enterprise positioning, but the data shows its performance is far below the consumer-oriented GTX 1080, which launched at 599 USD. For anyone choosing between these two end-of-life cards, the GTX 1080 is the only rational pick based on the benchmark evidence.