AMD Radeon HD 7790 vs NVIDIA Tesla K40c Comparison

FAQ

Q: Which GPU has the higher measured benchmark score?

A: The AMD Radeon HD 7790 scores 17,666 in Geekbench Metal, while the NVIDIA Tesla K40c scores 17,468 in Geekbench OpenCL. The HD 7790 leads by 198 points, a difference of roughly 1.1%.

Q: How do these cards compare to modern GPUs in their respective benchmark pools?

A: Both sit at the 61st percentile against all GPUs. The HD 7790 is 0.2% behind the NVIDIA GeForce RTX 4060 (17,639) and 0.4% ahead of the AMD Radeon 780M (17,588). The Tesla K40c is 1.0% behind the RTX 4060 and 0.7% behind the AMD Radeon 780M.

Q: Which card has more memory and bandwidth?

A: The Tesla K40c has 12 GB of GDDR5 on a 384-bit bus with 288.4 GB/s bandwidth. The HD 7790 has 1 GB of GDDR5 on a 128-bit bus with 96.00 GB/s bandwidth. That is a 12x capacity advantage and a 3x bandwidth advantage for the Tesla.

Q: What are the power requirements for each card?

A: The HD 7790 is rated at 85 W TDP with a 250 W suggested PSU and a single 6-pin connector. The Tesla K40c is rated at 245 W TDP with a 550 W suggested PSU and requires both a 6-pin and an 8-pin connector.

Q: Do both cards support the same modern APIs?

A: The HD 7790 supports DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.2.170. The Tesla K40c supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175. The HD 7790 has a higher DirectX feature level, while the Tesla has a slightly newer Vulkan version.

Q: Which card has display outputs?

A: The HD 7790 has 1x DVI, 1x HDMI 1.4a, and 2x mini-DisplayPort 1.2. The Tesla K40c has no display outputs at all, making it strictly a compute-oriented board.

The Verdict

The data presents two very different tools. The AMD Radeon HD 7790 is a compact, power-efficient graphics card meant for a desktop with a monitor attached. It delivers a slightly higher benchmark score in its tested workload (17,666 Metal vs 17,468 OpenCL), uses 160 W less power, and fits in a shorter 183 mm package. The NVIDIA Tesla K40c is a compute accelerator with 12 GB of memory, a 384-bit bus, and nearly three times the raw FP32 throughput (5.046 TFLOPS vs 1.792 TFLOPS), but it has no display outputs and demands a 550 W PSU.

For a builder assembling a small gaming or general-purpose rig, the HD 7790 is the obvious pick. It has display connectivity, a 250 W PSU requirement, and a single 6-pin connector. For anyone doing GPU-accelerated compute workloads that need large memory capacity or massive bandwidth, the Tesla K40c is the choice — the 12 GB frame buffer and 288.4 GB/s memory bandwidth are in a different class. The benchmark scores are nearly identical in this specific comparison, but the underlying hardware capabilities diverge sharply.

The launch MSRP for the HD 7790 was 149 USD. The launch MSRP for the Tesla K40c was 7,699 USD.

Head-to-Head Benchmarks

The head-to-head benchmark list is empty, so the comparison relies on the single benchmark each card was tested with. The HD 7790's Geekbench Metal score of 17,666 edges out the Tesla K40c's Geekbench OpenCL score of 17,468 by 198 points. That is a 1.1% margin, which is within noise for most real-world workloads.

However, the context matters. The HD 7790 achieves that score with 896 shading units, 56 TMUs, and 16 ROPs. The Tesla K40c uses 2,880 shading units, 240 TMUs, and 48 ROPs. The Tesla's pixel rate is 52.56 GPixel/s versus 16.00 GPixel/s for the HD 7790, and its texture rate is 210.2 GTexel/s versus 56.00 GTexel/s. The benchmark result does not reflect the Tesla's massive hardware advantage, likely because the workloads differ (Metal vs OpenCL) and the Tesla's architecture is tuned for compute, not graphics rasterization.

The nearest rival data reinforces the picture. The HD 7790's closest competitors are the RTX 4060 (+0.2% faster), Radeon 780M (+0.4% slower), and Radeon Pro 560 (+0.7% slower). The Tesla K40c's nearest rivals are the Radeon Pro 460 (-0.2% slower), Radeon Pro 560 (-0.5% slower), and Radeon 780M (-0.7% slower). Both cards are effectively clustered within 1% of modern mid-range GPUs in their respective benchmark pools.

Specification Differences

The two cards differ on nearly every specification that matters. The HD 7790 has 1,024 MB of GDDR5 memory on a 128-bit bus with 96.00 GB/s bandwidth. The Tesla K40c has 12 GB of GDDR5 memory on a 384-bit bus with 288.4 GB/s bandwidth. Memory clock is essentially identical (1500 MHz vs 1502 MHz).

Compute resources are dramatically different. The HD 7790 has 896 shading units, 56 TMUs, and 16 ROPs. The Tesla K40c has 2,880 shading units, 240 TMUs, and 48 ROPs — exactly 3.2x, 4.3x, and 3.0x more, respectively. FP32 throughput is 1.792 TFLOPS for the HD 7790 versus 5.046 TFLOPS for the Tesla.

Power and physical specs diverge. The HD 7790 is 85 W TDP, 183 mm long, dual-slot, with a 1x 6-pin connector and 250 W suggested PSU. The Tesla K40c is 245 W TDP, 267 mm long, dual-slot, with a 1x 6-pin + 1x 8-pin connector and a 550 W suggested PSU. The HD 7790 has display outputs; the Tesla has none.

Process node is the same (28 nm, TSMC), but transistor counts differ hugely: 2,080 million for the HD 7790 versus 7,080 million for the Tesla. Die size is 160 mm² versus 561 mm², and transistor density is 13.0M/mm² versus 12.6M/mm².

Architecture Differences

The HD 7790 uses the Bonaire chip with GCN 2.0 architecture, part of the Southern Islands generation (HD 7700 family). The Tesla K40c uses the GK180 chip with Kepler architecture, part of the Tesla Kepler generation (Kxx family). Both are built on TSMC's 28 nm process, but the design philosophies are opposite.

GCN 2.0 is a graphics-first architecture with a high degree of parallelism per CU, designed to handle both rasterization and compute workloads efficiently. It supports DirectX 12 (12_0), which is a full-feature implementation. Kepler, by contrast, is a compute-first architecture with a massive number of CUDA cores (2,880) arranged for throughput, but it only supports DirectX 12 (11_0), meaning it lacks some modern feature levels.

The Tesla's transistor budget (7,080 million) is spent on raw compute resources — 240 TMUs, 48 ROPs, and a 384-bit memory controller. The HD 7790's smaller transistor count (2,080 million) is balanced across a 128-bit memory bus, fewer TMUs/ROPs, and a more modest compute array. The Tesla also has a boost clock of 876 MHz (base 745 MHz), while the HD 7790 has no listed base or boost clocks in the data.

Both cards support OpenGL 4.6 and Vulkan (1.2.170 for AMD, 1.2.175 for NVIDIA). The HD 7790's predecessor is Northern Islands and its successor is Sea Islands. The Tesla K40c's predecessor is Tesla Fermi and its successor is Tesla Maxwell.

Where Each One Wins

AMD Radeon HD 7790 wins on:

• Benchmark score: 17,666 vs 17,468 — a 1.1% lead.
• Power efficiency: 85 W TDP vs 245 W means you can run it on a 250 W PSU instead of a 550 W unit.
• Physical footprint: 183 mm length vs 267 mm fits in smaller cases.
• Connectivity: Display outputs (DVI, HDMI 1.4a, 2x mini-DisplayPort 1.2) vs none.
• DirectX feature level: 12_0 vs 11_0.
• Single power connector: 1x 6-pin vs 1x 6-pin + 1x 8-pin.

NVIDIA Tesla K40c wins on:

• Memory capacity: 12 GB vs 1 GB — a 12x advantage for large datasets.
• Memory bandwidth: 288.4 GB/s vs 96.00 GB/s — a 3x advantage.
• Raw compute: 5.046 TFLOPS FP32 vs 1.792 TFLOPS — a 2.8x advantage.
• Texture and pixel throughput: 210.2 GTexel/s vs 56.00 GTexel/s; 52.56 GPixel/s vs 16.00 GPixel/s.
• Shader resources: 2,880 shading units vs 896, 240 TMUs vs 56, 48 ROPs vs 16.
• Vulkan version: 1.2.175 vs 1.2.170.

The use-case split is clean. Pick the HD 7790 for a desktop with a display, where power draw and physical size matter, and where you need DirectX 12_0 support. Pick the Tesla K40c for headless compute servers, machine learning inference, or any workload where 12 GB of VRAM and 288.4 GB/s of bandwidth are non-negotiable. The benchmark scores are nearly tied, but the hardware tells a different story: one is a graphics card, the other is a compute accelerator that happens to share a benchmark pool.