AMD Radeon HD 7970M vs NVIDIA Tesla K40c Comparison

The NVIDIA Tesla K40c and AMD Radeon HD 7970M represent two distinct approaches to high-performance graphics from the same 28 nm manufacturing generation, yet they target vastly different segments: a compute-oriented workstation accelerator versus a mobile gaming GPU. The benchmark data, derived from a single OpenCL workload, shows a narrow but definitive margin for the Tesla K40c.

Head-to-Head Benchmarks

In the only available comparative test, the Geekbench OpenCL benchmark, the NVIDIA Tesla K40c scores 17,468 points against the AMD Radeon HD 7970M’s 17,019 points. This yields a 2.6% advantage for the NVIDIA card, a relatively slim margin given the substantial architectural and specification differences between the two. While the Tesla K40c wins the single benchmark and holds a 1-0 win record in the head-to-head comparison, the delta is modest enough to suggest that real-world application performance could vary depending on workload characteristics.

The Tesla K40c’s 2.6% lead places it in the 61st percentile of all GPUs, while the HD 7970M sits just behind in the 60th percentile. When examining the nearest rivals for the Tesla K40c, the data shows a tightly clustered group: the AMD Radeon Pro 460 (17,509) trails by 0.2%, the AMD Radeon Pro 560 (17,551) by 0.5%, the AMD Radeon 780M (17,588) by 0.7%, and the NVIDIA GeForce RTX 4060 (17,639) by 1%. This suggests the Tesla K40c’s performance is competitive with much newer hardware, despite its 2013 release date.

For the AMD Radeon HD 7970M, the nearest rivals paint a similar picture of tight competition. The NVIDIA GeForce GTX 690 (17,037) leads by 0.1%, the AMD Radeon RX 7600 XT (17,083) by 0.4%, and the NVIDIA GeForce RTX 3070 (17,208) by 1.1%. The only rival that trails the HD 7970M is the NVIDIA Tesla M4 (16,932), which is 0.5% behind. These figures indicate that the HD 7970M, despite being a mobile part from 2012, still holds its own against significantly more recent desktop and mobile GPUs in this specific compute benchmark.

Where Each One Wins

The NVIDIA Tesla K40c wins in the compute throughput domain, as evidenced by its higher OpenCL score. This aligns with its design purpose as a Tesla-branded accelerator intended for scientific computing, deep learning, and other general-purpose GPU workloads. The data shows a 2.6% performance advantage, which, while not overwhelming, is consistent across the board in the single test available. The Tesla K40c’s advantage likely stems from its higher raw compute resources, including significantly more shading units and texture mapping units.

The AMD Radeon HD 7970M does not win any benchmark in this comparison, but its competitive score (within 2.6%) suggests it excels in scenarios where its lower power envelope and mobile form factor are advantageous. The HD 7970M’s 100 W TDP, compared to the Tesla K40c’s 245 W, makes it suitable for laptop implementations where thermal and power constraints are paramount. The HD 7970M also offers a different feature set, including portable-device-dependent display outputs, which the Tesla K40c completely lacks. For a mobile workstation user needing OpenCL compute, the HD 7970M provides a substantial portion of the Tesla K40c’s performance at a fraction of the power draw.

The benchmark results indicate that the Tesla K40c is the stronger pure compute performer, but the HD 7970M’s proximity in score, coupled with its dramatically lower power consumption, makes it a more practical choice for mobile or power-constrained environments. The Tesla K40c’s 12 GB of memory versus the HD 7970M’s 2 GB also suggests a clear divide: the Tesla is built for large datasets, while the HD 7970M targets more modest workloads.

Architecture Differences

The two GPUs employ fundamentally different architectures. The NVIDIA Tesla K40c is built on the Kepler architecture with the GK180 chip, part of the Tesla Kepler (Kxx) generation. The AMD Radeon HD 7970M uses the GCN 1.0 architecture with the Wimbledon chip, belonging to the London (HD 7900M) generation. Both are fabricated by TSMC on a 28 nm process node, but their internal designs diverge significantly.

The transistor counts reveal a massive difference in complexity. The Tesla K40c contains 7,080 million transistors on a 561 mm² die, resulting in a transistor density of 12.6M per mm². The HD 7970M, by contrast, houses 2,800 million transistors on a 212 mm² die, with a slightly higher density of 13.2M per mm². This means the Tesla K40c uses roughly 2.5 times more transistors and occupies 2.6 times more silicon area, underscoring its role as a high-end compute accelerator with more execution resources.

Memory architecture also differs substantially. The Tesla K40c ships with 12 GB of GDDR5 memory on a 384-bit bus, delivering 288.4 GB/s of bandwidth. The HD 7970M offers 2 GB of GDDR5 on a 256-bit bus, with 153.6 GB/s of bandwidth. The Tesla K40c therefore provides six times the memory capacity and nearly double the bandwidth, which is critical for compute workloads that require large datasets to reside on the GPU.

The compute resource allocation further highlights their divergent purposes. The Tesla K40c features 2,880 shading units, 240 texture mapping units, and 48 raster output units. The HD 7970M has 1,280 shading units, 80 TMUs, and 32 ROPs. This translates to a peak FP32 performance of 5.046 TFLOPS for the Tesla K40c versus 2.176 TFLOPS for the HD 7970M. The Tesla K40c’s pixel rate of 52.56 GPixel/s and texture rate of 210.2 GTexel/s dwarf the HD 7970M’s 27.20 GPixel/s and 68.00 GTexel/s, respectively.

Specification Differences

The specification sheets for these two GPUs reveal several key differences beyond raw performance. The Tesla K40c has a base clock of 745 MHz and a boost clock of 876 MHz, while the HD 7970M lists no base or boost clocks in the data. Memory clock speeds also differ: the Tesla K40c runs at 1502 MHz (6 Gbps effective), whereas the HD 7970M uses 1200 MHz (4.8 Gbps effective).

Power and physical specifications show stark contrasts. The Tesla K40c has a TDP of 245 W, requires a dual-slot cooler, and needs both a 6-pin and an 8-pin power connector, with a suggested power supply of 550 W. The HD 7970M is an MXM module with a 100 W TDP and no additional power connectors, making it suitable for laptops. The Tesla K40c measures 267 mm (10.5 inches) in length, while the HD 7970M has no listed dimensions due to its mobile form factor.

Bus interfaces differ as well: the Tesla K40c uses PCIe 3.0 x16, while the HD 7970M uses MXM-B (3.0). Display outputs are another major differentiator – the Tesla K40c has no outputs, being a compute-only card, while the HD 7970M supports portable-device-dependent outputs. API support is nearly identical, with both offering DirectX 12 (11_0 for NVIDIA, 11_1 for AMD), OpenGL 4.6, and Vulkan (1.2.175 for NVIDIA, 1.2.170 for AMD). The release dates show the HD 7970M launched on 2013-10-07, while the Tesla K40c came later on 2012-04-23. The Tesla K40c succeeded Tesla Fermi and was succeeded by Tesla Maxwell, while the HD 7970M succeeded Vancouver and was succeeded by Solar System.

FAQ

Q: Which GPU is faster in OpenCL compute workloads?

A: The NVIDIA Tesla K40c scores 17,468 in Geekbench OpenCL, which is 2.6% higher than the AMD Radeon HD 7970M’s 17,019, making it the faster card in this test.

Q: What is the memory capacity difference between the two?

A: The Tesla K40c has 12 GB of GDDR5 memory on a 384-bit bus with 288.4 GB/s bandwidth. The HD 7970M has 2 GB of GDDR5 on a 256-bit bus with 153.6 GB/s bandwidth.

Q: How do their power requirements compare?

A: The Tesla K40c has a 245 W TDP and requires a 6-pin plus 8-pin power connector with a 550 W suggested PSU. The HD 7970M has a 100 W TDP and uses no additional power connectors, being an MXM module.

Q: Are there differences in display output capabilities?

A: Yes, the Tesla K40c has no display outputs, while the HD 7970M supports portable-device-dependent outputs.

Q: Which architecture does each GPU use?

A: The Tesla K40c uses NVIDIA’s Kepler architecture with the GK180 chip. The HD 7970M uses AMD’s GCN 1.0 architecture with the Wimbledon chip.

Q: How do their shading unit counts affect performance?

A: The Tesla K40c has 2,880 shading units, enabling 5.046 TFLOPS FP32 performance. The HD 7970M has 1,280 shading units, yielding 2.176 TFLOPS, which explains the Tesla’s higher compute throughput.