AMD Radeon R6 M255DX vs NVIDIA Quadro 4000M Comparison

The Verdict

The NVIDIA Quadro 4000M and AMD Radeon R6 M255DX represent two vastly different approaches to mobile graphics, separated by three years of GPU evolution. The Quadro 4000M, a 2011-era professional mobile workstation part built on Fermi architecture, targets compute-heavy professional workloads with its 336 shading units and dedicated GDDR5 memory. The Radeon R6 M255DX, a 2014 hybrid graphics solution built on GCN 1.0, integrates its GPU with system memory as an IGP, prioritizing power efficiency and shared-memory flexibility over raw dedicated bandwidth.

Benchmark data shows the Quadro 4000M holds a 7.1% raw score advantage in its Geekbench OpenCL result (5211 vs 4867 for the Radeon), but the comparison is nuanced by the fact that the two GPUs were tested under different benchmark APIs. The Quadro 4000M sits at the 30th percentile among all GPUs, while the Radeon R6 M255DX sits at the 28th percentile — a statistically narrow gap that places both firmly in entry-level territory for their respective eras.

The verdict splits along usage patterns. For users running legacy professional applications that favor OpenCL compute and need the 2 GB dedicated GDDR5 frame buffer with 80.00 GB/s of bandwidth, the Quadro 4000M is the clear choice. Its 256-bit memory bus and 32 ROPs give it a substantial memory throughput advantage that the Radeon cannot match with its system-shared memory. Conversely, the Radeon R6 M255DX offers DirectX 12 (11_1) support and Vulkan 1.2.170 API compatibility — features absent from the Quadro's feature set — making it the better pick for anyone needing modern API support in a low-power integrated package.

The Radeon wins on architectural efficiency. Its 28 nm process node packs 690 million transistors into a 56 mm² die, achieving a transistor density of 12.3M per mm² versus the Quadro's 5.9M per mm² from its older 40 nm process and 332 mm² die. The Quadro's 1,950 million transistor count is nearly three times higher, but it consumes far more power at 100 W TDP compared to the Radeon's unlisted (but clearly IGP-class) power envelope. For a thin-and-light laptop with no discrete power connector, the Radeon is the only viable option. For a bulky mobile workstation with MXM module cooling, the Quadro's extra horsepower justifies its existence.

Ultimately: Choose the Quadro 4000M for legacy professional OpenCL compute and dedicated memory bandwidth. Choose the Radeon R6 M255DX for modern API support, efficiency, and integrated simplicity.

FAQ

Q: Which GPU has the higher benchmark score?

A: The NVIDIA Quadro 4000M scores 5211 in Geekbench OpenCL, while the AMD Radeon R6 M255DX scores 4867 in Geekbench Vulkan. This represents a 7.1% advantage for the Quadro, though the different benchmark APIs mean the comparison is not apples-to-apples.

Q: What are the closest competitors to each GPU?

A: The Quadro 4000M's nearest rival is the NVIDIA GeForce GTX 760M at 5236 (0.5% ahead), followed by the AMD Radeon R7 M260X at 5161 (1% behind). The Radeon R6 M255DX's closest rival is the NVIDIA GeForce GTX 560M at 4855 (0.2% ahead), with the NVIDIA GeForce 940MX at 4844 (0.5% behind).

Q: How do their memory configurations differ?

A: The Quadro 4000M uses 2 GB of dedicated GDDR5 memory on a 256-bit bus with 80.00 GB/s bandwidth. The Radeon R6 M255DX uses system-shared memory with a system-dependent bus width and bandwidth, meaning it has no dedicated video memory of its own.

Q: Which GPU supports more modern graphics APIs?

A: The Radeon R6 M255DX supports DirectX 12 (11_1), OpenGL 4.6, and Vulkan 1.2.170. The Quadro 4000M supports DirectX 12 (11_0) and OpenGL 4.6 but has no Vulkan support listed.

Q: What are the physical form factor differences?

A: The Quadro 4000M uses an MXM Module slot (MXM-B 3.0 interface) with a 100 W TDP and no power connectors. The Radeon R6 M255DX is an IGP (integrated graphics processor) with no TDP listed and no power connector requirement, making it suitable for compact systems.

Q: Which GPU has better pixel and texture throughput?

A: The Radeon R6 M255DX has a slightly higher pixel rate at 6.840 GPixel/s versus 6.650 GPixel/s for the Quadro. However, the Quadro dominates texture rate at 26.60 GTexel/s versus 17.10 GTexel/s, and FP32 compute at 638.4 GFLOPS versus 547.2 GFLOPS.

Architecture Differences

The two GPUs come from entirely different architectural lineages. The NVIDIA Quadro 4000M uses the GF104 chip built on Fermi architecture, fabricated on a 40 nm process at TSMC. Fermi was NVIDIA's compute-focused architecture, and the data reflects that priority: 336 shading units, 56 TMUs, and 32 ROPs are arranged to maximize parallel throughput. The chip contains 1,950 million transistors on a large 332 mm² die, yielding a modest transistor density of 5.9M per mm² — a reflection of the older, less dense process node.

The AMD Radeon R6 M255DX uses the Jet chip built on GCN 1.0 (Graphics Core Next) architecture, fabricated on a 28 nm process also at TSMC. GCN 1.0 was AMD's unified shader architecture that emphasized compute and graphics balance. The chip contains 690 million transistors on a tiny 56 mm² die, achieving a transistor density of 12.3M per mm² — more than double the Quadro's density. Despite having fewer transistors, the Radeon packs 320 shading units (close to the Quadro's 336), but only 20 TMUs and 8 ROPs.

The architectural philosophy differs sharply. Fermi's design favors raw compute and texture throughput, as evidenced by the Quadro's 26.60 GTexel/s texture rate and 638.4 GFLOPS FP32 performance. GCN 1.0's design favors efficiency and modern API support, with the Radeon achieving only 17.10 GTexel/s and 547.2 GFLOPS FP32 but offering DirectX 12 (11_1) and Vulkan 1.2.170 — APIs that postdate Fermi by years.

Clock behavior also differs. The Radeon has explicit base and boost clocks at 780 MHz and 855 MHz respectively, allowing dynamic power management. The Quadro lists no base or boost clock, only a memory clock of 625 MHz (2.5 Gbps effective). The Radeon's memory is system-shared with no dedicated clock, while the Quadro's GDDR5 runs at a fixed 625 MHz.

The Radeon's integrated nature means it relies on system memory bandwidth, which the data labels as "System Dependent." This is a fundamental architectural difference: the Quadro has guaranteed 80.00 GB/s of dedicated bandwidth, while the Radeon's bandwidth varies with the host system's memory configuration.

Specification Differences

| Specification | NVIDIA Quadro 4000M | AMD Radeon R6 M255DX |

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

| Chip | GF104 | Jet |

| Architecture | Fermi | GCN 1.0 |

| Process Node | 40 nm | 28 nm |

| Transistors | 1,950 million | 690 million |

| Die Size | 332 mm² | 56 mm² |

| Transistor Density | 5.9M / mm² | 12.3M / mm² |

| Base Clock | Not listed | 780 MHz |

| Boost Clock | Not listed | 855 MHz |

| Memory Clock | 625 MHz (2.5 Gbps effective) | System Shared |

| Memory Size | 2 GB GDDR5 | System Shared |

| Memory Bus Width | 256 bit | System Shared |

| Memory Bandwidth | 80.00 GB/s | System Dependent |

| Shading Units | 336 | 320 |

| TMUs | 56 | 20 |

| ROPs | 32 | 8 |

| Pixel Rate | 6.650 GPixel/s | 6.840 GPixel/s |

| Texture Rate | 26.60 GTexel/s | 17.10 GTexel/s |

| FP32 | 638.4 GFLOPS | 547.2 GFLOPS |

| TDP | 100 W | Not listed |

| Slot Width | MXM Module | IGP |

| Bus Interface | MXM-B (3.0) | IGP |

| DirectX | 12 (11_0) | 12 (11_1) |

| Vulkan | Not listed | 1.2.170 |

| Release Date | 2011-02-21 | 2014-01-06 |

Head-to-Head Benchmarks

The head-to-head benchmark table is empty, meaning no direct same-test comparison exists. Instead, the data provides one benchmark per GPU from different test suites: the Quadro 4000M ran Geekbench OpenCL and scored 5211, while the Radeon R6 M255DX ran Geekbench Vulkan and scored 4867. This 344-point gap (7.1%) is the only direct numerical comparison available.

The Quadro 4000M's biggest advantages are in throughput metrics. Its texture rate of 26.60 GTexel/s is 55.6% higher than the Radeon's 17.10 GTexel/s — a massive lead for texture-bound workloads. Its FP32 compute of 638.4 GFLOPS is 16.7% higher than the Radeon's 547.2 GFLOPS, and its 56 TMUs versus 20 TMUs give it nearly three times the texture unit count. Memory bandwidth is where the Quadro runs away: 80.00 GB/s dedicated versus a system-dependent figure that cannot match a dedicated 256-bit bus.

The Radeon R6 M255DX counters with a slight pixel rate advantage of 6.840 GPixel/s versus 6.650 GPixel/s (2.9% higher), despite having only 8 ROPs versus the Quadro's 32. This is a surprising result that suggests the Radeon's higher clock speeds (855 MHz boost versus the Quadro's unlisted clocks) help compensate for lower ROP counts. The Radeon also wins on API support: DirectX 12 (11_1) versus the Quadro's DirectX 12 (11_0), and Vulkan 1.2.170 support that the Quadro entirely lacks.

In the rivalry context, the Quadro 4000M's 5211 score places it just 0.5% behind the GeForce GTX 760M (5236) and 1% ahead of the Radeon R7 M260X (5161). The Radeon R6 M255DX's 4867 score puts it 0.2% behind the GeForce GTX 560M (4855) and 0.5% ahead of the GeForce 940MX (4844). Both GPUs cluster tightly with their peers — neither is an outlier in its performance class.

The practical takeaway from the benchmark data: the Quadro 4000M delivers meaningfully higher throughput in texture and compute operations, making it the stronger choice for OpenCL-style workloads that dominated professional mobile computing in its era. The Radeon R6 M255DX, despite lower raw throughput, offers modern API compatibility and a more efficient design that makes it the more future-proof choice for basic graphics tasks on contemporary software stacks. The 7.1% score gap is real but modest; the architectural and specification differences are far more decisive for real-world selection.