AMD Radeon R6 M255DX vs AMD Radeon R7 M440 Comparison

Head-to-Head Benchmarks

The database records a single direct head-to-head comparison between these two mobile graphics processors: Geekbench Vulkan. The AMD Radeon R7 M440 posts a score of 5751, while the AMD Radeon R6 M255DX trails at 4867. That is an 18.2% advantage for the R7 M440, a substantial margin in a GPU benchmark where single-digit percentage differences often separate close competitors.

This result places the R7 M440 in a different performance tier entirely. Its average benchmark score across all recorded tests sits at 5483, which lands it in the 32nd percentile of all GPUs in the database. The R6 M255DX, by contrast, averages 4867 and sits in the 28th percentile. The percentile gap matters: the R7 M440 is ahead of roughly a third of all recorded GPUs, while the R6 M255DX falls behind more than two-thirds of them.

Looking at the nearest rivals for each card reinforces this separation. The R7 M440's closest competitors include the NVIDIA Quadro M4000 at 5467 (a mere 0.3% behind the R7), the NVIDIA GeForce GTX 765M at 5501 (0.3% ahead), and the NVIDIA GeForce MX130 at 5508 (0.5% ahead). The AMD Radeon 610M sits at 5444, which is 0.7% behind the R7 M440. These are tight groupings, meaning the R7 M440 trades blows with mid-range discrete notebook GPUs from a few generations back.

The R6 M255DX's nearest rivals tell a different story. The NVIDIA GeForce GTX 560M scores 4855, just 0.2% behind the R6. The NVIDIA GeForce 940MX scores 4844, 0.5% behind. The NVIDIA GeForce GTS 450 scores 4893, 0.5% ahead. Even the NVIDIA GeForce RTX 5060 Ti 8 GB shows up at 4901 in this comparison, scoring 0.7% ahead, which is an oddity of the database's clustering algorithm rather than a meaningful performance equivalence. In any case, the R6 M255DX sits alongside older discrete cards and entry-level mobile parts, roughly 900 points below the R7 M440's Vulkan result.

The recorded data shows exactly one head-to-head test, and the R7 M440 wins it outright. There are no benchmark results where the R6 M255DX comes out ahead. The wins tally stands at 1 for the R7 M440 and 0 for the R6 M255DX.

Where Each One Wins

The R7 M440 wins the only benchmark the database records for both cards, and it does so decisively. In Geekbench Vulkan, the 18.2% lead translates to a real-world advantage in any workload that leverages the Vulkan API, which includes modern game engines and compute applications. The R7 M440 also has a second recorded benchmark, Geekbench OpenCL, where it scores 5214. That test is not run on the R6 M255DX, but it confirms the R7 M440's capability in general-purpose GPU compute tasks beyond just graphics rendering.

For the R6 M255DX, there is no benchmark in the database where it outperforms the R7 M440. Its only recorded score is the Geekbench Vulkan result of 4867, and that is the lower number in the head-to-head comparison. The data does not support any use case where the R6 M255DX wins outright. Its best case is simply being close to the R7 M440 in scenarios where the 18.2% gap narrows, but no such scenario appears in the measurements.

The use-case split is therefore clear. The R7 M440 is the choice for Vulkan-based gaming and compute workloads. The R6 M255DX offers no measured advantage anywhere in the database. If a workload relies on OpenCL, the R7 M440 has a recorded score of 5214, while the R6 M255DX has no OpenCL entry at all, so there is no basis for claiming the R6 can compete there either. The R6 M255DX's only potential niche would be in systems where its system-shared memory architecture is a requirement, but even then, the performance data does not favor it.

Architecture Differences

The two GPUs come from different generations of AMD's Graphics Core Next architecture. The R7 M440 uses GCN 3.0, built on the Meso chip. The R6 M255DX uses the original GCN 1.0, built on the Jet chip. This is a significant architectural gap: GCN 3.0 includes refinements in instruction scheduling, memory compression, and power management that GCN 1.0 lacks.

The process node is identical at 28 nm, and both are fabricated by TSMC. However, the chips differ dramatically in size and complexity. The R7 M440's Meso chip contains 1,550 million transistors on a 125 mm² die, yielding a transistor density of 12.4 million per mm². The R6 M255DX's Jet chip contains 690 million transistors on a 56 mm² die, with a density of 12.3 million per mm². The R7 M440 packs more than twice the transistors onto more than twice the die area, which explains its higher performance ceiling.

The memory architecture is another fundamental difference. The R7 M440 has dedicated 4 GB of DDR3 memory on a 64-bit bus, providing 14.40 GB/s of bandwidth. The R6 M255DX uses system-shared memory, meaning it borrows from the host system's RAM with bandwidth that is "System Dependent." This is a major disadvantage for the R6: dedicated memory offers consistent, predictable latency and bandwidth, while shared memory competes with the CPU for the same memory controller resources.

The R7 M440 belongs to the "Gem System (R7 M400)" generation, while the R6 M255DX belongs to the "Gem System Hybrid (Rx M200)" generation. The "Hybrid" designation hints at the R6's reliance on shared system memory rather than dedicated VRAM. The R7 M440's generation is newer, released in 2016 compared to the R6's 2014 release date.

DirectX support also differs. The R7 M440 supports DirectX 12 (12_0), while the R6 M255DX supports DirectX 12 (11_1). This means the R7 M440 can expose certain DirectX 12 features that the R6 cannot, which could matter for compatibility with the latest game titles. Both support OpenGL 4.6 and Vulkan 1.2.170.

Specification Differences

The most striking specification difference is in memory configuration. The R7 M440 has 4 GB of dedicated DDR3 memory with a 64-bit bus and 14.40 GB/s bandwidth. The R6 M255DX has "System Shared" memory in every memory field: size, type, bus width, and bandwidth are all listed as system-shared or system-dependent. There is no dedicated VRAM on the R6.

Clock speeds tell a partial story. The R6 M255DX has a recorded base clock of 780 MHz and a boost clock of 855 MHz. The R7 M440 has no base or boost clock recorded, but its memory clock is 900 MHz with 1800 Mbps effective data rate. The R6's memory clock is listed as "System Shared," so no direct memory clock comparison is possible.

Compute resources are identical in count: both have 320 shading units, 20 texture mapping units, and 8 raster operations pipelines. However, the clock differences lead to different throughput figures. The R7 M440 achieves 7.128 GPixel/s pixel rate, 17.82 GTexel/s texture rate, and 570.2 GFLOPS of FP32 compute. The R6 M255DX achieves 6.840 GPixel/s, 17.10 GTexel/s, and 547.2 GFLOPS. The R7 M440 leads by roughly 4-5% in each of these raw throughput metrics, which is consistent with its higher effective clock speeds.

The R7 M440 supports FP16 at a 1:1 ratio with FP32, delivering 570.2 GFLOPS. The R6 M255DX has no FP16 data recorded. This could matter for workloads that use half-precision arithmetic, such as certain machine learning inference tasks or image processing filters.

The bus interface differs as well. The R7 M440 uses PCIe 3.0 x8, which allows it to communicate with the host over a dedicated expansion bus. The R6 M255DX uses "IGP," meaning it is integrated into the chipset or processor package and communicates over the internal bus. Both are listed as "IGP" in slot width, confirming they are not discrete add-in cards.

Transistor counts differ substantially: 1,550 million for the R7 M440 versus 690 million for the R6 M255DX. Die size is 125 mm² versus 56 mm². The R7 M440's production status is "End-of-life," as is the R6's. The R7 M440 has a predecessor listed as "Solar System" and a successor as "Polaris Mobile," while the R6 M255DX has neither.

FAQ

Q: Which GPU is faster in Vulkan workloads?

A: The AMD Radeon R7 M440 scores 5751 in Geekbench Vulkan, which is 18.2% higher than the AMD Radeon R6 M255DX's 4867. The R7 M440 wins the only head-to-head test in the database.

Q: Do both GPUs have the same number of shading units?

A: Yes, both have 320 shading units, 20 texture mapping units, and 8 ROPs. The performance difference comes from clock speeds and memory architecture, not raw unit counts.

Q: How does the memory configuration differ?

A: The R7 M440 has 4 GB of dedicated DDR3 memory on a 64-bit bus with 14.40 GB/s bandwidth. The R6 M255DX uses system-shared memory, where size, type, bus width, and bandwidth are all system-dependent.

Q: What generation of GCN architecture does each GPU use?

A: The R7 M440 uses GCN 3.0 on the Meso chip, while the R6 M255DX uses GCN 1.0 on the Jet chip. The R7 M440's architecture is newer and includes more transistors: 1,550 million versus 690 million.

Q: Which GPU has better DirectX 12 support?

A: The R7 M440 supports DirectX 12 (12_0), while the R6 M255DX only supports DirectX 12 (11_1). Both support OpenGL 4.6 and Vulkan 1.2.170.

Q: Is there any benchmark where the R6 M255DX wins?

A: No. The database records one head-to-head benchmark, Geekbench Vulkan, and the R7 M440 wins it. The R6 M255DX has no recorded wins in any comparison.

The Verdict

The data points to a clear choice. The AMD Radeon R7 M440 outperforms the AMD Radeon R6 M255DX by 18.2% in the only benchmark where both are measured, and it holds advantages in nearly every recorded specification. The R7 M440's dedicated 4 GB of DDR3 memory provides 14.40 GB/s of bandwidth, while the R6 M255DX relies on system-shared memory with no guaranteed bandwidth figure. The R7 M440 also has a newer architecture, GCN 3.0 versus GCN 1.0, and a larger chip with more than double the transistors.

The R7 M440 sits in the 32nd percentile of all GPUs, grouping with discrete mobile parts like the NVIDIA Quadro M4000 and GeForce GTX 765M. The R6 M255DX sits in the 28th percentile, grouping with older discrete parts like the GeForce GTX 560M and GeForce 940MX. The percentile difference is modest, but the raw score gap of roughly 900 points in Vulkan is not.

For a user choosing between two systems with these GPUs, the R7 M440 is the pick for any Vulkan-based gaming or compute application. It also has a recorded OpenCL score of 5214, giving it a second measured workload where the R6 has no data at all. The R6 M255DX offers no measured advantage anywhere in the database.

There is one caveat worth noting: both GPUs are end-of-life products, and both are integrated parts with no recorded TDP or power connector requirements. The R7 M440's PCIe 3.0 x8 interface suggests it may be a discrete chip soldered to the motherboard or a small module, while the R6 M255DX's IGP bus interface confirms it is integrated. Neither is suitable for modern high-end gaming, but for light gaming and general GPU-accelerated tasks, the R7 M440 is clearly the stronger option based on the recorded data.