AMD Radeon HD 6850 X2 vs NVIDIA GeForce GT 740M Comparison

The AMD Radeon HD 6850 X2 and NVIDIA GeForce GT 740M are separated by nearly two years of GPU architecture evolution, yet their benchmark results place them in an unusually tight contest. The data shows a single head-to-head benchmark where the AMD card wins by a razor-thin margin of 0.1%, scoring 3977 against the NVIDIA’s 3974 in Geekbench OpenCL. This near-parity is striking given that the HD 6850 X2 is a dual-GPU desktop monster with a 254 W TDP, while the GT 740M is a 33 W mobile chip. The numbers suggest that raw compute throughput is not the only factor at play; memory bandwidth, driver efficiency, and architectural differences all collide here to produce a statistical dead heat.

Head-to-Head Benchmarks

The only direct comparison available is Geekbench OpenCL, and it is remarkably close. The AMD Radeon HD 6850 X2 edges out the NVIDIA GeForce GT 740M with a score of 3977 versus 3974, a delta of just 0.1%. In practical terms, this is a tie—the sort of margin that falls within run-to-run variance on any given test. However, the AMD card’s win is notable because it achieves this with fundamentally different hardware resources. The HD 6850 X2 fields 960 shading units, 48 texture mapping units, and 32 raster output units, while the GT 740M has 384 shading units, 32 TMUs, and only 8 ROPs. On paper, the AMD card has 2.5 times the shading units and 4 times the ROPs, yet it only outperforms by 0.1%. This suggests that the GT 740M’s Kepler 2.0 architecture is far more efficient per shader, or that the OpenCL workload is not fully saturating both cards’ resources.

Looking at the broader context, the AMD HD 6850 X2’s average benchmark score sits at 3977, placing it in the 24th percentile of all GPUs. Its nearest rivals include the NVIDIA Quadro K2000 (3964, +0.3%), the GeForce 830M (3957, +0.5%), and the Radeon R5 M420 (3956, +0.5%). The GT 740M, meanwhile, has an average score of 3717 (22nd percentile), which is dragged down by its additional Vulkan benchmark of 3459—a test the AMD card does not have. In OpenCL alone, the two are inseparable, but the GT 740M’s Vulkan result reveals a capability the HD 6850 X2 lacks entirely. The AMD card has no Vulkan score listed, which hints at a software support gap rather than a pure hardware one.

The deltaPct values against their nearest rivals further illustrate the knife-edge nature of these results. The HD 6850 X2 is within 0.6% of its closest competitors, while the GT 740M is within 1.9% of its own nearest rivals, including the AMD Radeon HD 6770 (3649, +1.9%). Neither card dominates its peer group; both are mid-pack performers from their respective eras. The single head-to-head win for the AMD card is real, but it is not a victory that translates into a meaningful performance advantage in any real-world sense.

Architecture Differences

The two GPUs come from opposite design philosophies. The AMD Radeon HD 6850 X2 is built on the Barts chip using TeraScale 2 architecture, manufactured on a 40 nm process at TSMC. It packs 1,700 million transistors into a 255 mm² die, yielding a transistor density of 6.7 million per square millimeter. This is a dual-GPU card from the Northern Islands generation, released in September 2011. Its memory subsystem is a 256-bit bus running GDDR5 at 1050 MHz (4.2 Gbps effective), delivering 134.4 GB/s of bandwidth. The card’s compute power is listed at 1.536 TFLOPS FP32, with pixel rate of 25.60 GPixel/s and texture rate of 38.40 GTexel/s.

In contrast, the NVIDIA GeForce GT 740M uses the GK208 chip with Kepler 2.0 architecture, on a 28 nm process, also from TSMC. It contains 1,020 million transistors on a much smaller 87 mm² die, giving it a higher transistor density of 11.7M per mm². This is a mobile chip from the GeForce 700M generation, released in June 2013. Its memory is a 64-bit bus with DDR3 at 900 MHz (1800 Mbps effective), providing just 14.40 GB/s of bandwidth—less than 11% of the AMD card’s bandwidth. The GT 740M’s FP32 throughput is 793.3 GFLOPS, roughly half of the HD 6850 X2’s. Its pixel rate is 8.264 GPixel/s and texture rate is 33.06 GTexel/s.

The architectural gap is stark. The AMD card has 2.5x the shading units, 1.5x the TMUs, 4x the ROPs, and 9.3x the memory bandwidth. Yet it only wins OpenCL by 0.1%. This implies that the GT 740M’s Kepler 2.0 architecture extracts far more usable performance per FLOP and per byte of bandwidth. The 40 nm TeraScale 2 design is older and less efficient; the 28 nm Kepler 2.0 is a later, more refined architecture with better instruction-level parallelism and occupancy management. The GT 740M also supports Vulkan 1.2.175 and DirectX 12 (11_0), while the AMD card stops at DirectX 11.2 and OpenGL 4.4 with no Vulkan support. This is a generational software advantage for NVIDIA.

Where Each One Wins

Based on the available data, the AMD Radeon HD 6850 X2 wins in raw compute metrics across the board. It has higher FP32 throughput (1.536 TFLOPS vs 793.3 GFLOPS), higher pixel fill rate (25.60 GPixel/s vs 8.264 GPixel/s), and higher texture fill rate (38.40 GTexel/s vs 33.06 GTexel/s). The memory bandwidth advantage is enormous—134.4 GB/s versus 14.40 GB/s—which would favor workloads that are bandwidth-bound, such as large texture streaming, high-resolution framebuffer operations, or compute tasks that repeatedly access memory. The 256-bit GDDR5 interface is a desktop-class design, while the 64-bit DDR3 is a mobile compromise.

The NVIDIA GeForce GT 740M wins in the only benchmark that tests API compatibility beyond OpenCL. Its Geekbench Vulkan score of 3459 demonstrates functional Vulkan support, which the AMD card lacks entirely. This is a meaningful win for modern workloads, as Vulkan is the foundation of many current game engines and compute frameworks. The GT 740M also has a higher transistor density (11.7M vs 6.7M per mm²), indicating a more efficient use of silicon area. Its power envelope is dramatically lower—33 W versus 254 W—which is a win for any system where thermal or power constraints matter, despite not being a direct performance metric.

The GT 740M’s boost clock of 1033 MHz (base 980 MHz) gives it a clock speed advantage over the AMD card, which has no listed base or boost clocks, only a memory clock of 1050 MHz. This higher core frequency helps the NVIDIA chip close the gap in compute despite having fewer shaders. For workloads that are latency-sensitive or lightly threaded, the GT 740M’s faster clocks may translate into better responsiveness, even if aggregate throughput is lower.

FAQ

Q: Which GPU has the higher OpenCL benchmark score?

A: The AMD Radeon HD 6850 X2 scores 3977, which is 0.1% higher than the NVIDIA GeForce GT 740M’s 3974 in Geekbench OpenCL. This is the only head-to-head benchmark listed, and the AMD card wins it.

Q: How does the memory bandwidth compare between the two?

A: The AMD Radeon HD 6850 X2 has 134.4 GB/s of bandwidth via a 256-bit GDDR5 interface, while the NVIDIA GeForce GT 740M has 14.40 GB/s via a 64-bit DDR3 interface. The AMD card has roughly 9.3 times the memory bandwidth.

Q: Does the NVIDIA GeForce GT 740M support Vulkan?

A: Yes, the GT 740M lists Vulkan 1.2.175 support and has a Geekbench Vulkan score of 3459. The AMD Radeon HD 6850 X2 has no Vulkan support listed and no Vulkan benchmark score.

Q: What is the transistor density difference?

A: The NVIDIA GeForce GT 740M has a transistor density of 11.7 million per mm², while the AMD Radeon HD 6850 X2 has 6.7 million per mm². This reflects the newer 28 nm process versus the older 40 nm process.

Q: Which card has a higher pixel fill rate?

A: The AMD Radeon HD 6850 X2 has a pixel rate of 25.60 GPixel/s, which is over three times higher than the NVIDIA GeForce GT 740M’s 8.264 GPixel/s.

Q: How do their average benchmark scores compare to their nearest rivals?

A: The AMD card’s average score of 3977 places it within 0.6% of its nearest rivals (NVIDIA Quadro K2000, GeForce 830M, Radeon R5 M420). The NVIDIA card’s average of 3717 places it within 1.9% of its nearest rivals (Quadro 3000M, GeForce 825M, GeForce GT 635M, Radeon HD 6770).

Specification Differences

| Specification | AMD Radeon HD 6850 X2 | NVIDIA GeForce GT 740M |

|---|---|---|

| 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 |

| Shading Units | 960 | 384 |

| TMUs | 48 | 32 |

| ROPs | 32 | 8 |

| Pixel Rate | 25.60 GPixel/s | 8.264 GPixel/s |

| Texture Rate | 38.40 GTexel/s | 33.06 GTexel/s |

| FP32 | 1.536 TFLOPS | 793.3 GFLOPS |

| TDP | 254 W | 33 W |

| Slot Width | Dual-slot | MXM Module |

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

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

| Display Outputs | 2x DVI, 1x HDMI, 1x DisplayPort | Portable Device Dependent |

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

| OpenGL | 4.4 | 4.6 |

| Vulkan | None | 1.2.175 |

| Release Date | 2011-09-18 | 2013-06-19 |

The Verdict

The data paints a clear picture of two GPUs from different worlds that happen to meet in the middle. The AMD Radeon HD 6850 X2 is a brute-force desktop solution: massive die, massive bandwidth, and massive power draw. Its 0.1% OpenCL win over the GT 740M reflects raw compute resources, but it is a hollow victory given the 254 W TDP required to sustain it. Anyone choosing the AMD card based on this benchmark must accept a dual-slot cooler, two 8-pin power connectors, a 600 W power supply recommendation, and the lack of Vulkan support. The card is end-of-life, and its 40 nm TeraScale 2 architecture is a dead end for modern API compatibility.

The NVIDIA GeForce GT 740M, despite losing the OpenCL head-to-head, is the more logical choice for most scenarios. Its 33 W TDP makes it suitable for thin laptops, its MXM form factor is portable, and it requires no external power connectors. The Vulkan 1.2.175 support with a score of 3459 gives it a path into modern compute and gaming workloads that the AMD card cannot access. The 28 nm process and higher transistor density indicate a more efficient design that achieves near-parity with less than a seventh of the power draw and a fraction of the memory bandwidth.

The verdict from the data: the AMD Radeon HD 6850 X2 wins on paper in every raw throughput metric, but the NVIDIA GeForce GT 740M wins on efficiency, API support, and practical usability. For desktop users with a robust power supply and a need for legacy DirectX 11 workloads, the AMD card’s 1.536 TFLOPS and 134.4 GB/s bandwidth are compelling. For anyone else—especially mobile users or those running Vulkan-based software—the GT 740M’s 3974 OpenCL score and 3459 Vulkan score make it the more future-proof option. The 0.1% delta in the only shared benchmark is statistically insignificant; the architectural and feature differences are what truly separate these two.