AMD Radeon HD 7790 vs NVIDIA GeForce GTX 780 Comparison

# NVIDIA GeForce GTX 780 vs AMD Radeon HD 7790

The NVIDIA GeForce GTX 780 and AMD Radeon HD 7790 represent two very different approaches to GPU design from the same 28 nm era, yet their benchmark results tell a surprising story. The GTX 780 is a large, power-hungry flagship built on the GK110 chip, while the HD 7790 is a compact, efficient mid-range card using the Bonaire chip with GCN 2.0 architecture. Despite the GTX 780's massive hardware advantage on paper, the available benchmark data shows the HD 7790 winning the only head-to-head test, which raises immediate questions about what each card is actually optimized for and where real-world performance diverges from theoretical specs.

Where Each One Wins

The sole head-to-head benchmark available is Geekbench Metal, and it goes decisively to the AMD Radeon HD 7790. The HD 7790 scores 17,666 in this test, while the GTX 780 manages only 10,114 — a delta of -42.7% for NVIDIA. This is a substantial margin, suggesting the HD 7790 has a significant advantage in Metal API workloads, which are primarily used in Apple ecosystem applications and content creation tasks. The GTX 780's much larger shading unit count and higher fill rates do not translate into Metal performance, indicating that architecture-level differences and driver optimization for this API heavily favor the GCN 2.0 design.

Looking at the broader benchmark landscape, the GTX 780 shows its strength in other areas. Its average benchmark score across all tests is 19,164, placing it in the 64th percentile of all GPUs. The HD 7790's average score is 17,666, which lands in the 61st percentile. While the HD 7790 wins the Metal test, the GTX 780's overall average is higher, suggesting it performs better across a wider range of compute workloads. The GTX 780 also has additional benchmark entries for OpenCL (22,863) and Vulkan (24,514), while the HD 7790 only has the Metal result, limiting direct comparisons. The data implies the GTX 780 is the more versatile card for general compute, while the HD 7790 has a specific niche where it excels.

Architecture Differences

The two cards could hardly be more different under the hood. The GTX 780 uses NVIDIA's GK110 chip with Kepler architecture, built on a 28 nm process at TSMC with 7,080 million transistors on a 561 mm² die. The HD 7790 uses AMD's Bonaire chip with GCN 2.0 architecture, also on TSMC's 28 nm process, but with just 2,080 million transistors on a 160 mm² die. This is a dramatic difference in scale — the GTX 780 has over three times the transistor count and more than three times the die area. Interestingly, the transistor density is nearly identical: 12.6M per mm² for the GTX 780 versus 13.0M per mm² for the HD 7790, reflecting the same manufacturing generation.

The compute resources differ enormously. The GTX 780 packs 2,304 shading units, 192 texture mapping units, and 48 ROPs. The HD 7790 has 896 shading units, 56 TMUs, and only 16 ROPs. These numbers explain why the GTX 780 achieves 4.156 TFLOPS of FP32 compute, 173.2 GTexel/s texture rate, and 43.30 GPixel/s pixel rate, while the HD 7790 delivers 1.792 TFLOPS, 56.00 GTexel/s, and 16.00 GPixel/s respectively. The GTX 780 is clearly the more powerful card on paper, with roughly 2.3 times the compute throughput and over 2.5 times the pixel fill rate.

Memory configurations also diverge sharply. The GTX 780 features 3 GB of GDDR5 on a 384-bit bus, yielding 288.4 GB/s of bandwidth. The HD 7790 has just 1024 MB of GDDR5 on a 128-bit bus, providing 96.00 GB/s. The GTX 780's memory bandwidth advantage is nearly 3x, which should help in bandwidth-intensive workloads like high-resolution textures and compute tasks. Both cards run their memory at effectively 6 Gbps, so the difference comes entirely from bus width and capacity.

FAQ

Q: Why does the AMD Radeon HD 7790 win the Geekbench Metal test despite having far fewer shading units and lower compute throughput?

A: The HD 7790 scores 17,666 versus the GTX 780's 10,114 in the Metal benchmark, a -42.7% delta for NVIDIA. This indicates that Metal API performance is not directly correlated with raw hardware specs like shading unit count or TFLOPS. The GCN 2.0 architecture in Bonaire appears better optimized for Metal workloads, possibly due to driver maturity or architectural features that favor this API's execution model.

Q: Which card has better overall compute performance across multiple APIs?

A: The GTX 780 has a higher average benchmark score of 19,164 compared to the HD 7790's 17,666, placing it in the 64th percentile versus the 61st. The GTX 780 also has scores in OpenCL (22,863) and Vulkan (24,514), while the HD 7790 only has a Metal score, suggesting the NVIDIA card is more consistent across different compute interfaces.

Q: How do the memory systems compare between these two cards?

A: The GTX 780 offers 3 GB of GDDR5 on a 384-bit bus with 288.4 GB/s bandwidth, while the HD 7790 has 1024 MB on a 128-bit bus with 96.00 GB/s. The GTX 780's bandwidth advantage is approximately 3x, which is significant for memory-heavy workloads.

Q: Are these cards from the same manufacturing process?

A: Yes, both use TSMC's 28 nm process. The GTX 780 has 7,080 million transistors on a 561 mm² die (12.6M per mm²), while the HD 7790 has 2,080 million transistors on a 160 mm² die (13.0M per mm²). The density is nearly identical, but the GTX 780 is physically much larger.

Q: What are the power requirements for each card?

A: The GTX 780 has a TDP of 250 W and requires a 600 W power supply, using 1x 6-pin and 1x 8-pin connectors. The HD 7790 has a TDP of just 85 W, needs a 250 W power supply, and uses a single 6-pin connector. The HD 7790 is far more power-efficient.

Q: Which card supports newer DirectX features?

A: The HD 7790 supports DirectX 12 (12_0), while the GTX 780 supports DirectX 12 (11_0). This means the AMD card has a newer feature level for DirectX 12, potentially enabling more advanced rendering features in games that use them.

Specification Differences

The most obvious differences are in raw compute resources. The GTX 780 has 2,304 shading units versus 896 on the HD 7790, 192 TMUs versus 56, and 48 ROPs versus 16. The FP32 performance is 4.156 TFLOPS versus 1.792 TFLOPS. Pixel rate is 43.30 GPixel/s versus 16.00 GPixel/s, and texture rate is 173.2 GTexel/s versus 56.00 GTexel/s.

Memory specifications differ substantially. The GTX 780 has 3 GB of GDDR5 on a 384-bit bus with 288.4 GB/s bandwidth, while the HD 7790 has 1024 MB on a 128-bit bus with 96.00 GB/s. The memory clock is nearly identical at 1502 MHz versus 1500 MHz, both translating to 6 Gbps effective.

The GTX 780's die is 561 mm² with 7,080 million transistors, while the HD 7790's die is 160 mm² with 2,080 million transistors. Transistor density is similar at 12.6M/mm² versus 13.0M/mm². Power consumption is a major differentiator: 250 W TDP versus 85 W, with the GTX 780 requiring a 600 W PSU and the HD 7790 needing only 250 W. The GTX 780 uses 1x 6-pin + 1x 8-pin connectors, while the HD 7790 uses just 1x 6-pin.

Physical dimensions also differ. The GTX 780 is 267 mm long, 111 mm tall, and 38 mm wide, while the HD 7790 is only 183 mm long with no listed height or width. Display outputs vary: the GTX 780 offers 2x DVI, 1x HDMI 1.4a, and 1x DisplayPort 1.2, while the HD 7790 provides 1x DVI, 1x HDMI 1.4a, and 2x mini-DisplayPort 1.2. The DirectX support differs as noted, with HD 7790 at 12_0 and GTX 780 at 11_0. The HD 7790 was released on 2013-03-21, about two months before the GTX 780's 2013-05-22 release.

Head-to-Head Benchmarks

The only direct comparison available is the Geekbench Metal test, and the result is striking. The AMD Radeon HD 7790 scores 17,666, while the NVIDIA GeForce GTX 780 scores 10,114, giving AMD a 42.7% advantage. This is not a marginal difference — it is a decisive victory for the smaller, cheaper, less powerful card on paper. The GTX 780 has 2.3x the FP32 throughput, 3x the memory bandwidth, and 3x the pixel rate, yet it loses badly in this specific workload.

This result becomes even more curious when looking at the GTX 780's other benchmark scores. Its OpenCL score of 22,863 and Vulkan score of 24,514 are both substantially higher than its Metal score, suggesting the card performs much better in other APIs. The HD 7790 has no OpenCL or Vulkan scores listed, so it is impossible to know whether it would maintain its advantage there. What the data does show is that Metal workloads on this GCN 2.0 card significantly outperform the Kepler architecture, which could be due to how each architecture handles the Metal API's command submission and resource binding models.

Looking at the nearest rivals provides context. The GTX 780's average score of 19,164 sits between the NVIDIA TITAN Xp at 19,177 (-0.1% delta) and the NVIDIA Tesla K20m at 19,089 (+0.4% delta). It is slightly ahead of the RTX 4050 Mobile (19,049, +0.6%) and RX 6600 (19,036, +0.7%). The HD 7790's average of 17,666 is close to the Quadro RTX 4000 at 17,789 (-0.7% delta), ahead of the RTX 4060 at 17,639 (+0.2%) and the Radeon 780M at 17,588 (+0.4%). These comparisons show both cards performing at levels comparable to much newer hardware in different ways — the GTX 780 trades blows with modern mid-range cards, while the HD 7790 holds its own against contemporary entries.

The Verdict

The data presents a nuanced picture. For users focused on Metal-based workloads — particularly in Apple ecosystems or content creation pipelines that leverage Metal — the AMD Radeon HD 7790 is the clear winner based on the available benchmark, with a 42.7% advantage over the GTX 780 in the only head-to-head test. Its lower power draw of 85 W versus 250 W, smaller physical footprint at 183 mm versus 267 mm, and newer DirectX 12 (12_0) support make it an attractive option for compact or low-power builds where Metal performance matters most.

For users prioritizing raw compute across multiple APIs, the NVIDIA GeForce GTX 780 appears stronger. Its higher average benchmark score of 19,164 versus 17,666, combined with strong OpenCL and Vulkan results, suggests broader capability. The 3 GB memory capacity and 288.4 GB/s bandwidth provide headroom for larger datasets that the HD 7790's 1024 MB and 96.00 GB/s cannot match. The GTX 780 also has more shading units, TMUs, and ROPs, which should benefit traditional rasterization workloads, though no game-specific benchmarks are available in the data.

The power efficiency argument favors AMD overwhelmingly. The HD 7790 delivers competitive Metal performance while consuming only 85 W, requiring just a 250 W power supply and a single 6-pin connector. The GTX 780 needs 250 W, a 600 W PSU, and dual power connectors. For users building low-power systems or upgrading older machines with modest power supplies, the HD 7790 is the practical choice.

The choice ultimately depends on the intended use case. The data cannot recommend the GTX 780 for Metal-centric workflows, given its large deficit there. Conversely, the HD 7790's lack of OpenCL and Vulkan benchmark results means its performance in those APIs is unknown, so users needing those capabilities should favor the GTX 780. Both cards are end-of-life products, but they serve very different niches despite being contemporaries. The GTX 780 is a compute powerhouse that underperforms in one specific API, while the HD 7790 is an efficiency-focused card that excels where it matters most for its target audience.