NVIDIA GeForce GTX 780 vs NVIDIA Tesla K40c Comparison

Where Each One Wins

The benchmark data splits these two Kepler cards into very different use cases. The NVIDIA GeForce GTX 780 is the clear winner in the only head-to-head test available, taking the Geekbench OpenCL score with 22,863 points against 17,468 points for the Tesla K40c, a 30.9% advantage. This is the GTX 780's only recorded benchmark win, but it is decisive in the compute workload measured.

The Tesla K40c, despite having no wins in the head-to-head comparison, is not without purpose. Its advantage lies in memory capacity. The K40c ships with 12 GB of GDDR5 memory, four times the 3 GB found on the GTX 780. That capacity difference does not show up in the OpenCL score, but it is the defining hardware specification for certain workloads. The GTX 780 targets graphics output with its display connectors, while the K40c has no display outputs at all, a clear signal that it is meant for compute-only environments.

The GTX 780 also holds the edge in the broader benchmark database. Its average benchmark score is 19,164, placing it in the 64th percentile of all GPUs. The K40c averages 17,468, sitting in the 61st percentile. Both are end-of-life products, but the GTX 780's higher percentile and higher average score indicate it remains the stronger performer in the tested OpenCL workload.

For gaming or general desktop use, the GTX 780 is the obvious choice. It has the display outputs, the higher clocks, and the benchmark win. The K40c, with its massive memory pool and no video outputs, is built for a different kind of job, one that requires holding large datasets on the card itself. The data does not show the K40c winning any speed test, but the memory configuration alone justifies its existence in compute racks.

Architecture Differences

Both cards are built on the same fundamental silicon. They share the 28 nm process node from TSMC, the same 7,080 million transistor count, and the same 561 mm² die size, giving both a transistor density of 12.6M per mm². Both use the Kepler architecture and both are manufactured by NVIDIA. The chip names differ, GK110 for the GTX 780 and GK180 for the Tesla K40c, but the underlying building blocks are nearly identical.

The compute resources differ significantly. The GTX 780 has 2,304 shading units, 192 texture mapping units, and 48 ROPs. The K40c scales that up to 2,880 shading units and 240 texture mapping units, while keeping the same 48 ROPs. That is a 25% increase in shading units and a 25% increase in TMUs, which explains why the K40c has higher theoretical rates. The K40c reaches 52.56 GPixel/s pixel rate and 210.2 GTexel/s texture rate, against 43.30 GPixel/s and 173.2 GTexel/s for the GTX 780. In raw FP32 compute, the K40c outputs 5.046 TFLOPS versus 4.156 TFLOPS.

Clock speeds tell the opposite story. The GTX 780 runs at a base clock of 863 MHz with a boost of 902 MHz. The K40c runs lower at 745 MHz base and 876 MHz boost. The GTX 780's higher clocks help close the gap in real-world performance, despite having fewer cores. Memory is identical in type and bus width: both use GDDR5 with a 384 bit interface and 288.4 GB/s bandwidth. The memory clock is also the same at 1502 MHz, listed as 6 Gbps effective.

The memory capacity difference is the biggest architectural divergence. The GTX 780 packs 3 GB, while the K40c holds 12 GB. Power consumption is close, 250 W TDP for the GTX 780 and 245 W for the K40c, with both using the same power connector layout, 1x 6-pin plus 1x 8-pin. The suggested PSU recommendation is 600 W for the GTX 780 and 550 W for the K40c. API support is identical: DirectX 12 (with the 11_0 feature level), OpenGL 4.6, and Vulkan 1.2.175. Neither card has ray tracing or tensor cores, neither has a game clock listed, and both are dual-slot width.

The release dates are close, May 2013 for the GTX 780 and October 2013 for the K40c. The GTX 780 belongs to the GeForce 700 generation, the K40c to the Tesla Kepler Kxx series. The GTX 780 has a predecessor in GeForce 600 and successor in GeForce 900, while the K40c follows Tesla Fermi and leads to Tesla Maxwell.

Head-to-Head Benchmarks

The only direct comparison in the database is Geekbench OpenCL, and the GTX 780 dominates it. The GTX 780 scores 22,863 points, while the K40c scores 17,468 points, a delta of 30.9% in favor of the GTX 780. That is a substantial margin, especially considering the K40c has more shading units and higher theoretical FP32 throughput.

The result is counterintuitive on paper. The K40c has 2,880 shading units, 240 TMUs, and 5.046 TFLOPS of FP32 compute. The GTX 780 has 2,304 shading units, 192 TMUs, and 4.156 TFLOPS. Yet the GTX 780 wins by nearly a third in the OpenCL benchmark. The likely explanation is the clock speed difference, 863 MHz base against 745 MHz base, combined with software or driver behavior that the database does not capture. The GTX 780's boost clock of 902 MHz also exceeds the K40c's 876 MHz.

The GTX 780's average benchmark score of 19,164 is higher than the K40c's 17,468, and the GTX 780 sits in the 64th percentile of all GPUs versus the K40c's 61st. In the nearest rival comparison, the GTX 780 is nearly tied with the NVIDIA TITAN Xp, which scores 19,177, a delta of only -0.1%. It also sits close to the Tesla K20m at 19,089 (0.4% ahead), the GeForce RTX 4050 Mobile at 19,049 (0.6% ahead), and the AMD Radeon RX 6600 at 19,036 (0.7% ahead). The K40c, meanwhile, trails its nearest rivals. The AMD Radeon Pro 460 scores 17,509, which is 0.2% ahead of the K40c. The Radeon Pro 560 is 0.5% ahead at 17,551, the AMD Radeon 780M is 0.7% ahead at 17,588, and the NVIDIA GeForce RTX 4060 is 1% ahead at 17,639.

The single head-to-head win gives the GTX 780 a 1-0 record in the database. The K40c has zero wins. For anyone choosing between these two strictly on benchmark performance, the GTX 780 is the faster card in OpenCL. The K40c wins only on memory capacity, which is not reflected in the recorded scores.

FAQ

Q: Which card is faster in the recorded benchmarks?

A: The NVIDIA GeForce GTX 780 is faster. It scores 22,863 in Geekbench OpenCL versus 17,468 for the Tesla K40c, a 30.9% advantage. The GTX 780 also has a higher average benchmark score of 19,164 against 17,468.

Q: Does the Tesla K40c have more compute cores than the GTX 780?

A: Yes. The K40c has 2,880 shading units and 240 texture mapping units, while the GTX 780 has 2,304 shading units and 192 texture mapping units. The K40c also has higher theoretical FP32 compute at 5.046 TFLOPS versus 4.156 TFLOPS.

Q: Why does the GTX 780 win if the K40c has more cores?

A: The GTX 780 runs at higher clocks, 863 MHz base and 902 MHz boost, compared to 745 MHz base and 876 MHz boost for the K40c. The benchmark results show the GTX 780 winning by 30.9% in OpenCL despite the K40c's larger core count.

Q: How much memory does each card have?

A: The GTX 780 has 3 GB of GDDR5 memory, while the K40c has 12 GB. The Tesla K40c has 1, 6 GB of GDDR5. Both use a 384 bit bus with 288.4 GB/s bandwidth. The K40c has four times the memory capacity.

Q: Can the Tesla K40c be used for display output?

A: No. The K40c has no display outputs. The GTX 780 has 2x DVI, 1x HDMI 1.4a, and 1x DisplayPort 1.2 outputs.

Q: How do these cards compare to their nearest rivals in the database?

A: The GTX 780 is nearly tied with the NVIDIA TITAN Xp, which is 0.1% ahead, and leads the Tesla K20m by 0.4%, the GeForce RTX 4050 Mobile by 0.6%, and the AMD Radeon RX 6600 by 0.7%. The K40c trails the AMD Radeon Pro 460 by 0.2%, the Radeon Pro 560 by 0.5%, the AMD Radeon 780M by 0.7%, and the NVIDIA GeForce RTX 4060 by 1%.

The Verdict

The GTX 780 is the better choice for anyone who needs a working graphics card with display output and higher benchmark scores. It wins the only head-to-head test by 30.9%, has a higher average score, a higher percentile ranking, and includes the display connectors that make it usable in a desktop. It runs at higher clocks, 863 MHz base and 902 MHz boost, and consumes 250 W TDP. Its launch MSRP was 649 USD.

The Tesla K40c is the better choice for workloads that need large on-card memory. Its 12 GB capacity is four times the GTX 780's 3 GB, and that is the single most important advantage it holds. It has more shading units, more TMUs, higher theoretical FP32, and slightly lower TDP at 245 W, but the benchmark data shows it losing the OpenCL test by a wide margin. Its launch MSRP was 7,699 USD.

The data is clear: in raw performance, the GTX 780 wins. The K40c's value rests entirely on its memory capacity and compute-oriented design, with no display outputs and a much higher launch price. For a general-purpose GPU, the GTX 780 is the pick. For a compute node where 12 GB of memory matters more than speed, the K40c has a role. The database records one head-to-head result, and it belongs to the GTX 780.