AMD Radeon HD 6850 X2 vs NVIDIA GeForce GT 735M Comparison

The AMD Radeon HD 6850 X2 and NVIDIA GeForce GT 735M occupy very different corners of the GPU landscape. The data shows a clear performance hierarchy, yet the story is more nuanced than a simple win/loss tally. This analysis examines the benchmark results, architectural philosophies, and feature sets to determine where each card's strengths truly lie.

Where Each One Wins

The AMD Radeon HD 6850 X2 is the undisputed performance champion in raw compute workloads. In the single available benchmark test, Geekbench OpenCL, it secures the only head-to-head victory. Its score of 3977 places it in the 24th percentile of all GPUs, which is modest in absolute terms but represents a significant margin over its rival. The HD 6850 X2's wins are rooted in its dual-GPU design philosophy, which prioritizes brute-force throughput for desktop gaming and compute tasks. It is a card built to push pixels and process data aggressively, with a peak FP32 throughput of 1.536 TFLOPS that dwarfs its competitor.

The NVIDIA GeForce GT 735M wins in a different arena: efficiency and integration. While it loses the performance contest, its 33 W TDP and IGP (integrated graphics processor) form factor mean it is designed for slim, portable laptops where power draw and heat are critical constraints. The data shows it has no benchmark wins against the HD 6850 X2, but its victory is in enabling a class of devices that the dual-slot, 254 W AMD card could never inhabit. The GT 735M's 21st percentile ranking is only 3 points lower than its rival, suggesting that in real-world mobile scenarios, the performance gap may be less impactful than the raw numbers imply. The GT 735M also wins on software feature support, offering DirectX 12 (11_0) and Vulkan 1.2.175, which the AMD card lacks entirely.

Architecture Differences

The two GPUs represent fundamentally different design generations and philosophies. The AMD Radeon HD 6850 X2 is built on the TeraScale 2 architecture, fabricated on a 40 nm process at TSMC. It utilizes the Barts chip, which packs 1,700 million transistors into a substantial 255 mm² die. This results in a transistor density of 6.7 million transistors per square millimeter. The architecture is a classic desktop brute-force design, with 960 shading units, 48 texture mapping units (TMUs), and 32 raster operation units (ROPs). The card is essentially a dual-GPU solution on a single board, explaining its massive 254 W TDP.

In contrast, the NVIDIA GeForce GT 735M uses the Kepler 2.0 architecture on a much more modern 28 nm process, also from TSMC. Its GK208 chip is far smaller at 87 mm² and houses 1,020 million transistors, yielding a higher density of 11.7 million transistors per square millimeter. This smaller, denser chip is designed for efficiency, with 384 shading units, 32 TMUs, and only 8 ROPs. The memory subsystem tells a similar story: the AMD card uses 2 GB of GDDR5 on a 256-bit bus, delivering 134.4 GB/s of bandwidth. The NVIDIA card uses 2 GB of DDR3 on a meager 64-bit bus, resulting in just 14.40 GB/s. This stark difference in memory bandwidth is a key factor in the performance gap.

The feature sets also diverge sharply. The HD 6850 X2 supports DirectX 11.2 (11_0) and OpenGL 4.4, but has no Vulkan support. The GT 735M, despite being a lower-performance part, supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175. This makes the NVIDIA card more future-proof for modern API applications. Additionally, the AMD card requires two 8-pin power connectors and a 600 W suggested power supply, while the GT 735M requires no external power connectors at all.

Head-to-Head Benchmarks

The only direct benchmark comparison available is Geekbench OpenCL, and the results are decisive. The AMD Radeon HD 6850 X2 scores 3977, while the NVIDIA GeForce GT 735M scores 3616. This gives the AMD card a 10% lead in this specific compute test. This is a substantial margin, indicating that for OpenCL-based workloads, the older, more power-hungry card is clearly superior.

Looking at the nearest rivals provides context. The HD 6850 X2's closest competitor is the NVIDIA Quadro K2000 with an average score of 3964, a negligible 0.3% difference. The NVIDIA GeForce 830M (3957) and AMD Radeon R5 M420 (3956) are also within 0.5%. This cluster suggests the HD 6850 X2 is competitive with a range of mid-range cards from its era. Interestingly, the GT 735M's nearest rival list includes the NVIDIA GeForce GTX 1050, which scores 3629, a 0.3% difference. This is surprising, as the GTX 1050 is a much more capable card in gaming, but the OpenCL scores suggest they are in the same compute ballpark. The GT 735M also sits close to the NVIDIA RTX 5000 Mobile Ada Generation (3596, 0.6% difference) and the NVIDIA GeForce GT 545 (3594, 0.6%), highlighting the narrow compute performance band these different cards occupy.

When you look at the deltaPct values, the AMD card's average benchmark score of 3977 is 10% higher than the NVIDIA's 3616. This is the single most important data point. It shows that in raw computational throughput, the HD 6850 X2 is not just slightly ahead; it is a clear step up. However, the GT 735M's performance is not catastrophic. It is within striking distance, especially when you consider that the GT 735M achieves this with a fraction of the power draw and a much smaller physical footprint.

The Verdict

The data presents a clear choice based on use case, not a universal winner. For any scenario requiring maximum compute performance, the AMD Radeon HD 6850 X2 is the obvious pick. Its 10% lead in Geekbench OpenCL, combined with its higher pixel rate (25.60 GPixel/s vs 5.024 GPixel/s) and texture rate (38.40 GTexel/s vs 20.10 GTexel/s), makes it the superior choice for tasks like rendering, scientific computing, or any application that can leverage its dual-GPU architecture. The raw numbers are unambiguous: 1.536 TFLOPS of FP32 performance versus 482.3 GFLOPS is a threefold advantage for AMD.

However, the NVIDIA GeForce GT 735M is the right choice for a completely different set of priorities. Its 33 W TDP and lack of power connectors mean it can be placed in thin, light laptops without active cooling solutions. Its support for DirectX 12 and Vulkan ensures compatibility with modern software APIs. The data shows it is a competent performer, even if it is not a leader. Its 3616 OpenCL score is only slightly below the HD 6850 X2's nearest rivals, and its 21st percentile ranking shows it is not a bottom-tier part.

Strictly from the data, the HD 6850 X2 is for desktop users who demand performance and have the power supply (600 W suggested) and physical space for a dual-slot card. The GT 735M is for mobile users who prioritize portability, battery life, and modern software support over raw speed. The GT 735M is not a gaming card by any stretch, but it is a capable multimedia and productivity solution for a laptop. The choice is not about which is "better" in a vacuum; it is about which is better for the intended environment.

FAQ

Q: Which GPU has a higher Geekbench OpenCL score?

A: The AMD Radeon HD 6850 X2 scores 3977, which is 10% higher than the NVIDIA GeForce GT 735M's score of 3616.

Q: What is the memory bandwidth difference between the two cards?

A: The AMD Radeon HD 6850 X2 has a memory bandwidth of 134.4 GB/s using GDDR5 on a 256-bit bus, while the NVIDIA GeForce GT 735M has 14.40 GB/s using DDR3 on a 64-bit bus.

Q: Does the NVIDIA GeForce GT 735M support Vulkan?

A: Yes, the GT 735M supports Vulkan 1.2.175. The AMD Radeon HD 6850 X2 does not have Vulkan support listed.

Q: What are the power requirements for each card?

A: The AMD Radeon HD 6850 X2 has a 254 W TDP and requires 2x 8-pin power connectors with a 600 W suggested power supply. The NVIDIA GeForce GT 735M has a 33 W TDP and requires no power connectors.

Q: Which GPU has a higher transistor density?

A: The NVIDIA GeForce GT 735M has a higher transistor density at 11.7 million transistors per mm², while the AMD Radeon HD 6850 X2 has 6.7 million per mm².

Q: What is the process node for each architecture?

A: The AMD Radeon HD 6850 X2 uses a 40 nm process, while the NVIDIA GeForce GT 735M uses a smaller 28 nm process.

Specification Differences

| Specification | AMD Radeon HD 6850 X2 | NVIDIA GeForce GT 735M |

| :--- | :--- | :--- |

| Architecture | TeraScale 2 | Kepler 2.0 |

| Process Node | 40 nm | 28 nm |

| Transistors | 1,700 million | 1,020 million |

| Die Size | 255 mm² | 87 mm² |

| Transistor Density | 6.7M / mm² | 11.7M / mm² |

| Memory Type | GDDR5 | DDR3 |

| Memory Bus Width | 256 bit | 64 bit |

| Memory Bandwidth | 134.4 GB/s | 14.40 GB/s |

| Memory Clock | 1050 MHz (4.2 Gbps effective) | 900 MHz (1800 Mbps effective) |

| Shading Units | 960 | 384 |

| TMUs | 48 | 32 |

| ROPs | 32 | 8 |

| Pixel Rate | 25.60 GPixel/s | 5.024 GPixel/s |

| Texture Rate | 38.40 GTexel/s | 20.10 GTexel/s |

| FP32 Performance | 1.536 TFLOPS | 482.3 GFLOPS |

| TDP | 254 W | 33 W |

| Slot Width | Dual-slot | IGP |

| Power Connectors | 2x 8-pin | None |

| Suggested PSU | 600 W | None |

| Bus Interface | PCIe 2.0 x16 | PCIe 3.0 x8 |

| DirectX Support | 11.2 (11_0) | 12 (11_0) |

| OpenGL Support | 4.4 | 4.6 |

| Vulkan Support | None | 1.2.175 |

| Release Date | 2011-09-18 | 2013-03-31 |