AMD Radeon HD 6770 vs NVIDIA GeForce GT 635M Comparison

The NVIDIA GeForce GT 635M and AMD Radeon HD 6770 are both end-of-life mobile and desktop graphics solutions, respectively, from the early 2010s. Benchmark data shows these two cards are remarkably close in overall compute performance, despite their vastly different internal designs and power requirements.

Head-to-Head Benchmarks

The only direct benchmark comparison available is the Geekbench OpenCL test. In this test, the NVIDIA GeForce GT 635M scores 3740 points, while the AMD Radeon HD 6770 scores 3649 points. This gives the NVIDIA card a 2.5% advantage, marking it as the winner in the sole head-to-head test.

This 2.5% delta is extremely tight. For context, the GT 635M sits just 0.6% above the NVIDIA Quadro 3000M (3718 points) and 0.6% above the GeForce GT 740M (3717 points). It is 1.2% ahead of the GeForce 825M (3694 points), while the Intel UHD Graphics 710 is 1.4% ahead of it (3792 points). On the AMD side, the HD 6770 is 0.6% ahead of the GeForce GTX 1050 (3629 points) and 0.9% ahead of the GeForce GT 735M (3616 points). It trails the GeForce 825M by 1.2%, but beats the RTX 5000 Mobile Ada Generation by 1.5% (3596 points).

The practical takeaway is that in raw OpenCL compute, these two cards are effectively interchangeable. The 2.5% lead for NVIDIA falls well within the noise of typical driver and thermal variations. Both cards land in the 22nd percentile of all GPUs, meaning they are entry-level performers by modern standards. Neither card is a powerhouse; they are both firmly in the "basic acceleration" tier.

FAQ

Q: Which GPU has the higher benchmark score?

A: The NVIDIA GeForce GT 635M scores 3740 in Geekbench OpenCL, which is 2.5% higher than the AMD Radeon HD 6770's score of 3649.

Q: How much memory bandwidth does each card have?

A: The AMD Radeon HD 6770 has 76.80 GB/s of bandwidth, which is more than 2.5 times the 28.80 GB/s available on the NVIDIA GeForce GT 635M.

Q: What is the power draw difference between the two?

A: The NVIDIA GeForce GT 635M has a TDP of 35 W, while the AMD Radeon HD 6770 draws 108 W. This makes the NVIDIA card roughly one-third the power consumption of the AMD card.

Q: Are these GPUs still supported by modern APIs?

A: The NVIDIA card supports DirectX 12 (11_0) and OpenGL 4.6, while the AMD card supports DirectX 11.2 (11_0) and OpenGL 4.4. Neither card supports Vulkan.

Q: What memory types do they use?

A: The NVIDIA GeForce GT 635M uses 2 GB of DDR3 memory, while the AMD Radeon HD 6770 uses 1024 MB of GDDR5 memory.

Q: Which card has a higher pixel fill rate?

A: The AMD Radeon HD 6770 has a pixel rate of 13.60 GPixel/s, which is over 7 times higher than the NVIDIA GeForce GT 635M's rate of 1.900 GPixel/s.

Where Each One Wins

The AMD Radeon HD 6770 wins decisively in raw throughput metrics. Its pixel rate of 13.60 GPixel/s dwarfs the NVIDIA card's 1.900 GPixel/s, making it far more capable for fill-rate-bound tasks like high-resolution texture mapping and simple 2D/3D compositing. Its texture rate of 34.00 GTexel/s is likewise 4.5 times the GT 635M's 7.600 GTexel/s, which matters for games that rely heavily on textured surfaces. The AMD card's FP32 performance of 1,360.0 GFLOPS is also significantly higher than the 182.4 GFLOPS of the NVIDIA part, indicating stronger raw math throughput when the workload scales well. The HD 6770 also offers 800 shading units versus 96, 40 TMUs versus 16, and 16 ROPs versus 4, giving it a structural advantage in parallel workloads.

The NVIDIA GeForce GT 635M wins in efficiency and integration. Its 35 W TDP makes it suitable for thin-and-light laptops where the 108 W HD 6770 would be impractical. The GT 635M is an IGP slot-width part with no power connectors, while the HD 6770 is a dual-slot card requiring a 1x 6-pin connector and a 300 W suggested PSU. In the Geekbench OpenCL test, the NVIDIA card also edges out the AMD card by 2.5%, showing that its lower raw specs do not translate to a compute disadvantage in this specific test.

Specification Differences

The most striking differences are in memory and compute resources. The NVIDIA GeForce GT 635M has 2 GB of DDR3 memory at 900 MHz (1800 Mbps effective), yielding 28.80 GB/s bandwidth over a 128-bit bus. The AMD Radeon HD 6770 has 1024 MB of GDDR5 at 1200 MHz (4.8 Gbps effective), yielding 76.80 GB/s over the same 128-bit bus width. The AMD card has more than double the bandwidth despite having half the capacity.

Compute units also diverge sharply. The GT 635M packs 96 shading units, 16 TMUs, and 4 ROPs. The HD 6770 has 800 shading units, 40 TMUs, and 16 ROPs. This translates to a pixel rate of 1.900 GPixel/s and texture rate of 7.600 GTexel/s for NVIDIA, versus 13.60 GPixel/s and 34.00 GTexel/s for AMD. FP32 performance is 182.4 GFLOPS versus 1,360.0 GFLOPS.

Power and physical specs are equally different. The GT 635M is a 35 W part with no power connectors and an IGP slot width. The HD 6770 is a 108 W dual-slot card requiring a 1x 6-pin connector and a 300 W suggested PSU. The HD 6770 is also a desktop card measuring 198 mm (7.8 inches) long, while the GT 635M is portable-device dependent. The AMD card's display outputs are 2x DVI, 1x HDMI 1.3a, and 2x mini-DisplayPort 1.1. The NVIDIA card's outputs are listed as "Portable Device Dependent."

Architecture Differences

The NVIDIA GeForce GT 635M is built on the Fermi architecture using the GF108 chip. It is fabricated on a 40 nm process at TSMC, with 585 million transistors on a 116 mm² die, giving a transistor density of 5.0M / mm². It is part of the GeForce 600M generation, succeeding the GeForce 500M and preceding the GeForce 700M.

The AMD Radeon HD 6770 uses the TeraScale 2 architecture with the Juniper chip. It is also on a 40 nm TSMC process, but packs 1,040 million transistors on a 166 mm² die, yielding a density of 6.3M / mm². It belongs to the Northern Islands (HD 6700) generation, succeeding Evergreen and preceding Southern Islands.

The transistor count difference is notable: the AMD chip has nearly double the transistors of the NVIDIA chip. This aligns with the AMD card's much higher shading unit count and fill rates. However, the NVIDIA card supports newer API versions, with DirectX 12 (11_0) versus DirectX 11.2 (11_0) and OpenGL 4.6 versus 4.4. Neither architecture includes ray tracing or tensor cores. The NVIDIA card was released on 2012-03-21, while the AMD card came earlier on 2011-01-20.

The Verdict

The data presents a clear split between compute efficiency and raw throughput. For users who need a low-power, integrated solution for light compute tasks, the NVIDIA GeForce GT 635M is the better choice. Its 35 W TDP, lack of power connectors, and IGP form factor make it suitable for portable devices where power draw and space are constrained. It also holds a small 2.5% lead in the Geekbench OpenCL benchmark, meaning it is not a performance sacrifice in that specific test.

For desktop users with a dedicated PSU and space for a dual-slot card, the AMD Radeon HD 6770 offers vastly superior raw specifications. Its 76.80 GB/s memory bandwidth, 13.60 GPixel/s pixel rate, and 1,360.0 GFLOPS of FP32 power make it the stronger candidate for memory-bandwidth-bound or fill-rate-bound workloads. The HD 6770's 800 shading units versus 96 give it a massive advantage in highly parallel compute tasks, even if the Geekbench OpenCL test does not reflect this.

The benchmark result is nearly a tie, but the architectures are not. The GT 635M wins on efficiency and API support; the HD 6770 wins on raw power and bandwidth. Choose the NVIDIA card for laptops or low-power builds, and the AMD card for desktop workstations where performance per watt is secondary to absolute throughput. The HD 6770's launch MSRP was 129 USD.