AMD Radeon HD 7790 vs NVIDIA Tesla K80 Comparison

The NVIDIA Tesla K80 and AMD Radeon HD 7790 represent two vastly different design philosophies from the same 28 nm TSMC process generation. The Tesla K80 is a dual-slot compute accelerator aimed at datacenter workloads, while the HD 7790 is a compact, power-efficient desktop graphics card. The benchmark data shows a clear performance hierarchy, with the K80 leading in raw compute scores, but the HD 7790’s architectural efficiency tells a different story. This analysis breaks down where each card excels, the underlying silicon differences, and what the numbers mean for specific use cases.

Where Each One Wins

The data splits cleanly along workload lines. The Tesla K80 dominates in pure compute throughput, as evidenced by its Geekbench scores. It achieves 18,620 in OpenCL and 19,111 in Vulkan, giving it an average benchmark score of 18,866. This places it in the 63rd percentile of all GPUs, positioning it just ahead of the NVIDIA GeForce RTX 2070 (18,789, +0.4% delta) and slightly behind the NVIDIA RTX 2000 Ada Generation (18,954, -0.5% delta). The K80’s strength is sustained, high-parallelism compute work, where its dual-GPU design and ample memory bandwidth shine.

The AMD Radeon HD 7790, by contrast, wins on efficiency and accessibility. Its sole benchmark result is a Geekbench Metal score of 17,666, which yields an average of 17,666 and a 61st percentile ranking. This is remarkably close to the K80’s average, trailing by only 1,200 points (roughly 6.4% lower). The HD 7790’s nearest rivals include the NVIDIA GeForce RTX 4060 (17,639, +0.2% delta) and the AMD Radeon 780M (17,588, +0.4% delta), showing it competes with much newer hardware in certain API-optimized tests. The HD 7790 wins in scenarios where power draw, physical size, and display output matter, as it offers 1 GB of memory, a 128-bit bus, and a 183 mm length compared to the K80’s 267 mm length and lack of display outputs.

Architecture Differences

The architectural gap is vast. The Tesla K80 uses the GK210 chip based on Kepler 2.0 architecture, featuring 7,100 million transistors on a 561 mm² die. This yields a transistor density of 12.7 million per mm². The HD 7790 uses the Bonaire chip based on GCN 2.0, with 2,080 million transistors on a 160 mm² die, achieving a slightly higher density of 13.0 million per mm². Both are fabricated by TSMC on the same 28 nm node, but the K80 packs more than three times the transistors.

The K80’s compute resources are massive: 2,496 shading units, 208 texture mapping units (TMUs), and 48 render output units (ROPs). The HD 7790 offers 896 shading units, 56 TMUs, and 16 ROPs. This 2.8x difference in shading units directly explains the K80’s higher FLOP counts. The K80 delivers 4.113 TFLOPS FP32, while the HD 7790 produces 1.792 TFLOPS. The K80’s pixel rate is 42.85 GPixel/s versus the HD 7790’s 16.00 GPixel/s, and its texture rate is 171.4 GTexel/s versus 56.00 GTexel/s.

Clock behavior also differs. The K80 has a base clock of 562 MHz and a boost clock of 824 MHz, while the HD 7790’s base and boost clocks are not specified in the data. The K80’s memory runs at 1253 MHz (5 Gbps effective), while the HD 7790’s memory runs at 1500 MHz (6 Gbps effective). Despite the HD 7790’s faster memory clock, the K80’s wider 384-bit bus gives it a bandwidth of 240.6 GB/s, far exceeding the HD 7790’s 96.00 GB/s from its 128-bit bus. The K80 uses 12 GB of GDDR5, while the HD 7790 uses only 1 GB.

Feature support diverges. The K80 supports DirectX 12 (11_1) and Vulkan 1.2.175, while the HD 7790 supports DirectX 12 (12_0) and Vulkan 1.2.170. Both offer OpenGL 4.6. The HD 7790 has display outputs (1x DVI, 1x HDMI 1.4a, 2x mini-DisplayPort 1.2), whereas the K80 has no outputs, confirming its headless compute role.

Head-to-Head Benchmarks

The head-to-head benchmark list is empty, so the comparison relies on their respective Geekbench results across different APIs. The K80’s OpenCL score of 18,620 and Vulkan score of 19,111 are its only registered tests. The HD 7790’s only test is Metal, scoring 17,666. These are not directly comparable metrics, but the averages provide a proxy. The K80’s average of 18,866 sits 1,200 points (6.8%) above the HD 7790’s 17,666.

The K80’s strongest relative showing is in Vulkan, where it scores 19,111, which is 8.2% higher than its own OpenCL score. This suggests the Kepler architecture handles Vulkan’s explicit compute model well. The HD 7790’s Metal score of 17,666 is impressive given its much smaller silicon, indicating that GCN 2.0 scales efficiently in API-optimized workloads. The K80’s nearest rival, the Quadro K6000 (19,030), is only 0.9% ahead, meaning the K80 is essentially at parity with that professional card. The HD 7790’s nearest rival, the Quadro RTX 4000 (17,789), is 0.7% ahead, showing the HD 7790 holds its own against a much newer professional GPU.

The biggest per-point win for the K80 is the raw compute lead. Its FP32 throughput of 4.113 TFLOPS is 2.3x the HD 7790’s 1.792 TFLOPS. Similarly, its texture rate of 171.4 GTexel/s is 3.1x higher, and its pixel rate of 42.85 GPixel/s is 2.7x higher. These figures translate directly to fill-rate-bound and shader-bound workloads. The HD 7790’s win is in efficiency: it achieves 61% of the K80’s average score while drawing 85 W versus the K80’s 300 W, a 3.5x power ratio. The HD 7790 also delivers its performance in a 183 mm card versus the K80’s 267 mm length.

Specification Differences

The following fields differ between the two cards, with the K80 listed first:

• Chip: GK210 vs Bonaire
• Architecture: Kepler 2.0 vs GCN 2.0
• Generation: Tesla Kepler (Kxx) vs Southern Islands (HD 7700)
• Transistors: 7,100 million vs 2,080 million
• Die Size: 561 mm² vs 160 mm²
• Transistor Density: 12.7M / mm² vs 13.0M / mm²
• Base Clock: 562 MHz vs not specified
• Boost Clock: 824 MHz vs not specified
• Memory Clock: 1253 MHz (5 Gbps effective) vs 1500 MHz (6 Gbps effective)
• Memory Size: 12 GB vs 1024 MB
• Memory Bus Width: 384 bit vs 128 bit
• Memory Bandwidth: 240.6 GB/s vs 96.00 GB/s
• Shading Units: 2496 vs 896
• TMUs: 208 vs 56
• ROPs: 48 vs 16
• Pixel Rate: 42.85 GPixel/s vs 16.00 GPixel/s
• Texture Rate: 171.4 GTexel/s vs 56.00 GTexel/s
• FP32: 4.113 TFLOPS vs 1.792 TFLOPS
• TDP: 300 W vs 85 W
• Power Connectors: 1x 8-pin vs 1x 6-pin
• Suggested PSU: 700 W vs 250 W
• Display Outputs: No outputs vs 1x DVI, 1x HDMI 1.4a, 2x mini-DisplayPort 1.2
• DirectX Support: 12 (11_1) vs 12 (12_0)
• Vulkan Support: 1.2.175 vs 1.2.170
• Dimensions (Length): 267 mm (10.5 inches) vs 183 mm (7.2 inches)
• Release Date: 2014-11-16 vs 2013-03-21
• Predecessor: Tesla Fermi vs Northern Islands
• Successor: Tesla Maxwell vs Sea Islands
• Launch MSRP: None vs 149 USD
• Benchmark Scores: Geekbench OpenCL 18,620 and Vulkan 19,111 vs Geekbench Metal 17,666
• Average Benchmark Score: 18,866 vs 17,666
• Percentile vs All GPUs: 63 vs 61

FAQ

Q: Which card has higher raw compute performance?

A: The Tesla K80 does. It delivers 4.113 TFLOPS FP32, which is 2.3x the HD 7790’s 1.792 TFLOPS. Its average benchmark score of 18,866 is also higher than the HD 7790’s 17,666.

Q: How does the memory configuration compare?

A: The K80 has 12 GB of GDDR5 on a 384-bit bus, yielding 240.6 GB/s bandwidth. The HD 7790 has 1 GB on a 128-bit bus, yielding 96.00 GB/s. The HD 7790’s memory clock is faster at 1500 MHz (6 Gbps effective) versus the K80’s 1253 MHz (5 Gbps effective), but the K80’s wider bus dominates.

Q: Which card is more power efficient?

A: The HD 7790 is dramatically more efficient. It has an 85 W TDP and requires a 250 W suggested PSU, while the K80 has a 300 W TDP and requires a 700 W PSU. The HD 7790 achieves 61% of the K80’s average score while drawing 28% of the power.

Q: Can either card output video?

A: Only the HD 7790 can. It has 1x DVI, 1x HDMI 1.4a, and 2x mini-DisplayPort 1.2 outputs. The K80 has no display outputs, making it strictly a compute device.

Q: What are their relative standings among all GPUs?

A: The K80 sits in the 63rd percentile, while the HD 7790 sits in the 61st. The K80’s nearest rival is the RTX 2070 (0.4% ahead of it), and the HD 7790’s nearest rival is the RTX 4060 (0.2% ahead of it).

Q: Which card supports a newer DirectX version?

A: The HD 7790 supports DirectX 12 (12_0), while the K80 supports DirectX 12 (11_1). The HD 7790’s version is newer in feature level, despite the K80 having higher compute throughput.

The Verdict

The data points to a clear split: the Tesla K80 is the compute specialist, and the HD 7790 is the efficiency-focused generalist. For workloads requiring massive FP32 throughput, large memory capacity, or high fill rates, the K80 is the superior choice. Its 4.113 TFLOPS, 12 GB memory, and 240.6 GB/s bandwidth are all roughly 2.3x to 2.5x the HD 7790’s figures. The K80’s 63rd percentile ranking and its parity with the RTX 2070 (within 0.4%) confirm it remains a viable compute card for its era.

The HD 7790, however, wins for desktop use and power-constrained environments. Its 85 W TDP, 183 mm length, and display outputs make it a practical card for a standard PC. Its Metal score of 17,666, which places it within 0.7% of the Quadro RTX 4000, shows that architectural efficiency can partially offset raw hardware disadvantages. Its 61st percentile is only 2 points behind the K80, despite using 2,080 million transistors versus 7,100 million.

Buyers should choose the K80 for datacenter-style compute tasks, headless rendering, or any scenario where raw numbers matter more than power draw. The HD 7790 is the pick for anyone needing a functional graphics card with modest power requirements, especially if the workload favors Metal or DirectX 12 (12_0) features. The K80’s lack of display outputs disqualifies it for most consumer builds. The HD 7790’s launch MSRP was 149 USD, a figure that contextualizes its market position, but both cards are now end-of-life. In short: the K80 computes harder, the HD 7790 computes smarter per watt.