AMD Radeon HD 7790 vs AMD Radeon HD 7970M Comparison

The AMD Radeon HD 7790 and the AMD Radeon HD 7970M represent two distinct approaches to the same 28 nm generation, with the data showing them separated by margins that are smaller than their architectural differences suggest. The HD 7790, a desktop card built on the Bonaire chip, posts a Geekbench Metal score of 17,666, while the HD 7970M, a mobile MXM module using the larger Wimbledon chip, scores 17,019 in Geekbench OpenCL. This places the HD 7790 in the 61st percentile of all GPUs and the HD 7970M in the 60th, making them effectively peers in overall performance despite their divergent designs.

The Verdict

The benchmark data indicates that the AMD Radeon HD 7790 is the stronger choice for users prioritizing raw compute performance in a desktop context. Its Geekbench Metal score of 17,666 edges out the HD 7970M’s OpenCL result of 17,019 by roughly 3.8%, a margin that, while not enormous, is consistent across the two cards’ relative positions against their nearest rivals. The HD 7790 sits within 0.2% of the NVIDIA GeForce RTX 4060 (17,639) and 0.4% of the AMD Radeon 780M (17,588), whereas the HD 7970M trails the GeForce RTX 3070 by 1.1% (17,208) and the RX 7600 XT by 0.4% (17,083). For a desktop builder, the HD 7790 offers a slightly higher performance ceiling and a more modern feature set, as its GCN 2.0 architecture supports DirectX 12 (12_0) compared to the HD 7970M’s DirectX 12 (11_1) capability.

However, the HD 7970M is not without its own appeal. The data shows it delivers higher peak throughput in several key metrics: it has 1,280 shading units versus 896, 80 texture mapping units versus 56, and 32 ROPs versus 16. Its 2 GB of GDDR5 memory on a 256-bit bus provides 153.6 GB/s of bandwidth, substantially more than the HD 7790’s 1 GB on a 128-bit bus at 96.00 GB/s. For users who need a mobile solution with greater memory capacity and bandwidth for larger textures or higher resolutions, the HD 7970M’s design makes it the more capable option in those specific areas, even if its overall compute score is slightly lower. The verdict hinges on use case: the HD 7790 wins on compute and API support, while the HD 7970M wins on memory throughput and raw pixel-pushing capacity.

Architecture Differences

The two GPUs share a 28 nm process node from TSMC, but they diverge sharply in chip design and generation. The HD 7790 uses the Bonaire chip, built on the GCN 2.0 architecture, and belongs to the Southern Islands generation under the HD 7700 family. It packs 2,080 million transistors into a 160 mm² die, yielding a transistor density of 13.0 million per square millimeter. The HD 7970M, in contrast, uses the Wimbledon chip with the older GCN 1.0 architecture, part of the London generation under the HD 7900M family. Its die is larger at 212 mm², housing 2,800 million transistors at a density of 13.2M per mm². This makes the HD 7970M physically larger and more complex, but the HD 7790’s newer architecture compensates with better efficiency per transistor in compute workloads.

Memory configurations differ significantly. The HD 7790 ships with 1,024 MB of GDDR5 memory on a 128-bit bus, running at 1,500 MHz with 6 Gbps effective speed, producing 96.00 GB/s of bandwidth. The HD 7970M doubles capacity to 2 GB on a 256-bit bus, with memory clocked at 1,200 MHz and 4.8 Gbps effective, yielding 153.6 GB/s. This 60% bandwidth advantage for the HD 7970M is a direct result of its wider bus and higher capacity, though the HD 7790’s faster memory clock partially offsets the gap in latency-sensitive tasks. The HD 7790’s pixel rate is 16.00 GPixel/s and texture rate is 56.00 GTexel/s, while the HD 7970M achieves 27.20 GPixel/s and 68.00 GTexel/s, respectively, reflecting its higher ROP and TMU counts.

Feature support also separates the two. The HD 7790’s GCN 2.0 architecture enables DirectX 12 (12_0), while the HD 7970M is limited to DirectX 12 (11_1). Both cards support OpenGL 4.6 and Vulkan 1.2.170, but the HD 7790 offers PCIe 3.0 x16 connectivity and a dual-slot desktop form factor with display outputs including 1x DVI, 1x HDMI 1.4a, and 2x mini-DisplayPort 1.2. The HD 7970M uses an MXM-B (3.0) interface, requires no power connectors, and its display outputs are portable-device dependent. The HD 7790 has a TDP of 85 W with a suggested PSU of 250 W and a 1x 6-pin connector, while the HD 7970M draws 100 W as an MXM module. The HD 7790’s launch MSRP is 149 USD, though no such figure exists for the HD 7970M.

Head-to-Head Benchmarks

Direct head-to-head benchmark data is absent from the record, so the comparison relies on each card’s single benchmark result against its nearest rivals. The HD 7790’s Geekbench Metal score of 17,666 places it just 0.2% ahead of the NVIDIA GeForce RTX 4060 (17,639) and 0.4% ahead of the AMD Radeon 780M (17,588). It also leads the AMD Radeon Pro 560 (17,551) by 0.7%, while trailing the NVIDIA Quadro RTX 4000 (17,789) by 0.7%. This tight clustering suggests the HD 7790 performs at a level comparable to modern mid-range GPUs in compute tasks, a remarkable outcome for a 2013-era card. The HD 7970M’s Geekbench OpenCL score of 17,019 is 0.1% behind the NVIDIA GeForce GTX 690 (17,037) and 0.4% behind the AMD Radeon RX 7600 XT (17,083), while leading the NVIDIA Tesla M4 (16,932) by 0.5% and trailing the GeForce RTX 3070 (17,208) by 1.1%.

The biggest win for the HD 7790 is its compute score advantage of 647 points over the HD 7970M, a 3.8% difference. This is notable because the HD 7970M has 43% more shading units and 43% more TMUs, yet still loses on the aggregate benchmark. The HD 7790’s GCN 2.0 architecture appears to extract more useful work per shader, likely due to improved instruction scheduling and better occupancy handling. The HD 7970M’s largest advantage lies in memory bandwidth: its 153.6 GB/s is 60% higher than the HD 7790’s 96.00 GB/s, and its pixel rate of 27.20 GPixel/s is 70% higher. In fill-rate-bound scenarios, such as high-resolution rendering with heavy alpha blending, the HD 7970M would likely pull ahead, though the single benchmark available does not capture that distinction.

FAQ

Q: Which GPU has the higher benchmark score?

A: The AMD Radeon HD 7790 scores 17,666 in Geekbench Metal, while the AMD Radeon HD 7970M scores 17,019 in Geekbench OpenCL. The HD 7790 leads by 647 points, or about 3.8%.

Q: How do these GPUs compare to modern cards in their nearest rival lists?

A: The HD 7790 is within 0.2% of the NVIDIA GeForce RTX 4060 (17,639) and 0.4% of the AMD Radeon 780M (17,588). The HD 7970M is 0.1% behind the GeForce GTX 690 (17,037) and 0.4% behind the AMD Radeon RX 7600 XT (17,083).

Q: What are the memory specifications of each card?

A: The HD 7790 has 1,024 MB of GDDR5 on a 128-bit bus with 96.00 GB/s bandwidth. The HD 7970M has 2 GB of GDDR5 on a 256-bit bus with 153.6 GB/s bandwidth.

Q: Which card supports a newer DirectX version?

A: The HD 7790 supports DirectX 12 (12_0), while the HD 7970M supports DirectX 12 (11_1). Both support OpenGL 4.6 and Vulkan 1.2.170.

Q: What are the TDP and form factor differences?

A: The HD 7790 has an 85 W TDP and is a dual-slot desktop card with PCIe 3.0 x16. The HD 7970M has a 100 W TDP and is an MXM module with an MXM-B (3.0) interface, requiring no power connectors.

Q: Which GPU has higher shading unit and ROP counts?

A: The HD 7970M has 1,280 shading units and 32 ROPs, versus the HD 7790’s 896 shading units and 16 ROPs. The HD 7970M also has 80 TMUs compared to 56.

Where Each One Wins

The AMD Radeon HD 7790 wins on compute performance and API modernity. Its Geekbench Metal score of 17,666 is higher than the HD 7970M’s 17,019, and its DirectX 12 (12_0) support is a full tier above the HD 7970M’s DirectX 12 (11_1). The HD 7790 also benefits from a smaller die (160 mm² versus 212 mm²) and lower transistor count (2,080 million versus 2,800 million), which contributes to its lower 85 W TDP and desktop-friendly dual-slot design with standard display outputs. For users running compute-heavy workloads or games that leverage DirectX 12 features, the HD 7790 is the clear pick. Its position relative to rivals reinforces this: it nearly matches the GeForce RTX 4060 and beats the Radeon 780M, whereas the HD 7970M sits slightly below the RX 7600 XT and GTX 690.

The AMD Radeon HD 7970M wins on memory capacity, bandwidth, and raw fill rate. Its 2 GB frame buffer, 256-bit bus, and 153.6 GB/s bandwidth provide a 60% advantage over the HD 7790’s 1 GB and 96.00 GB/s, which matters for texture-heavy assets and higher resolutions. Its 27.20 GPixel/s pixel rate and 68.00 GTexel/s texture rate are 70% and 21% higher, respectively, than the HD 7790’s 16.00 GPixel/s and 56.00 GTexel/s. The HD 7970M also has more shading units (1,280 versus 896) and TMUs (80 versus 56), giving it higher theoretical peak throughput. Its MXM form factor makes it suitable for laptop upgrades or custom portable builds, where the HD 7790’s desktop PCIe card cannot go. The HD 7970M’s 2 GB memory and higher fill rates make it the better choice for users who prioritize visual fidelity and high-resolution rendering over compute benchmarks.