AMD Radeon R6 M255DX vs NVIDIA GeForce GTX 980M Comparison

# NVIDIA GeForce GTX 980M vs AMD Radeon R6 M255DX: A Data-Driven Comparison

The NVIDIA GeForce GTX 980M and the AMD Radeon R6 M255DX sit at opposite ends of the mobile graphics spectrum, and the benchmark data makes the gap obvious. The GTX 980M is a high-end Maxwell 2.0 part with 1536 shading units, while the R6 M255DX is a low-end GCN 1.0 chip with 320 shaders. The average benchmark score of the GTX 980M is 5308, placing it in the 31st percentile of all GPUs in the database. The R6 M255DX averages 4,867 points, which places it in the 28th percentile. This 9% average score gap is just the beginning of the story.

Head-to-Head Benchmarks

In the head-to-head comparison, the database includes a Geekbench Vulkan run where the GTX 980M scored 17,703 points and the R6 M255DX scored 4,867 points. That is a 263.7% advantage for the NVIDIA part, a decisive win that shows the architectural gulf between these two mobile SKUs. The GTX 980M is based on the GM204 chip with 5.2 billion transistors and 1536 shader units. The R6 M255DX is built on the Jet chip, with 690 million transistors and 320 shader units. The NVIDIA part has 4.8 times more shader hardware, and its transistor count is roughly 7.5 times higher, which directly translates into the massive workload advantage.

Looking at the nearest rivals in our database, the GTX 980M's average score of 5,308 is very close to the NVIDIA GeForce 930A (5,317, -0.2%) and the NVIDIA GeForce 840M (5,322, -0.3%). It is also within 0.5% of the score of the NVIDIA GeForce 940M and within 0.9% of the AMD Radeon R7 M445. This indicates that, in the same performance bracket, the GTX 980M is a very competitive option. The R6 M255DX, on the other hand, with an average score of 4,867, is effectively tied with the NVIDIA GeForce GTX 560M (4,855, +0.2%) and the NVIDIA GeForce 940MX (4,844, +0.5%), and it is less than 0.7% behind the NVIDIA GeForce GTS 450 (4,893). These close numbers indicate the R6 M255DX sits at the upper edge of an older performance class, while the GTX 980M operates in a different league.

Where Each One Wins

NVIDIA GeForce GTX 980M Wins: 1 (Geekbench Vulkan)

The only direct head-to-head benchmark in the package is Geekbench Vulkan. The GeForce GTX 980M wins this test by a wide margin, 263.7%. The AMD part cannot compete with the NVIDIA part in raw compute. The Radeon has a very low score (4,867) and only 320 shader cores, which is a fraction of the 1,536 of the NVIDIA chip. The 980M is the clear winner in the one test where they actually run head-to-head.

AMD Radeon R6 M255DX Wins: 0

The R6 M255DX does not win any of the recorded benchmark tests. The only draw is in the closest rival comparisons, where it is within 1% of many older NVIDIA parts, but it loses on the only head-to-head test. If the workload is very light and the notebook's thermal design is the limiting factor, the R6 M255DX's lower power draw (system shared memory) could be an advantage. But from the pure benchmark data, the NVIDIA GeForce GTX 980M is the clear winner.

FAQ

Q: How much faster is the GTX 980M in the Geekbench Vulkan test?

A: The GTX 980M scores 17,703, while the Radeon R6 M255DX scores 4,867. That is a 263.7% difference. The NVIDIA part is 3.6 times faster in this specific test.

Q: What is the main difference in memory between the two parts?

A: The GTX 980M has 8 GB of dedicated GDDR5 memory on a 256-bit bus, for a bandwidth of 160.4 GB/s. The R6 M255DX uses System Shared memory, so its bandwidth is System Dependent. For memory-intensive loads, the dedicated VRAM of the NVIDIA part is a major advantage.

Q: Are there any differences in the shader cores?

A: Yes, a significant one. The GTX 980M has 1536 shading units, 96 TMUs, and 64 ROPs. The Radeon R6 M255DX has 320 shading units, 20 TMUs, and 8 ROPs. The NVIDIA part has 4.8 times the shader units and 4.8 times the TMUs/ROPs.

Q: What is the manufacturing process of both cards?

A: Both are made at TSMC on a 28nm process. The GeForce GTX 980M uses the GM204 chip with 5.2 billion transistors on a 398 mm² die, and the Radeon R6 M255DX uses the Jet chip with 690 million transistors on a 56 mm² die. The GTX 980M has a transistor density of 13.1 million per mm², while the AMD chip has 12.3 million per mm².

Q: What are their API support levels?

A: The GTX 980M supports DirectX 12 (12_1) and OpenGL 4.6 and Vulkan 1.4. The Radeon R6 M255DX supports DirectX 12 (11_1), OpenGL 4.6, and Vulkan 1.2.170.

Specification Differences

The two chips differ on almost every key specification. The NVIDIA GeForce GTX 980M is built on the Maxwell 2.0 architecture, using the GM204 chip. The AMD Radeon R6 M255DX uses the GCN 1.0 architecture and the Jet chip. NVIDIA has a 28nm process from TSMC, as does AMD. The NVIDIA chip counts 5.2 billion transistors, the AMD chip 690 million. The NVIDIA die is 398 mm², AMD is 56 mm². Transistor density is 13.1M/mm² for the NVIDIA chip, and 12.3M/mm² for the AMD chip.

Clocks differ greatly. The GTX 980M has a base clock of 1038 MHz and a boost of 1127 MHz. The R6 M255DX has a base clock of 780 MHz and a boost clock of 855 MHz. The NVIDIA part runs 258 MHz higher at base and 272 MHz higher at boost.

Memory is another major dividing line. The GTX 980M has 8 GB of GDDR5 memory on a 256-bit bus. The effective memory clock is 1253 MHz, and the effective bandwidth is 5 Gbps (160.4 GB/s). The Radeon R6 M255DX uses System Shared memory; bus width and bandwidth are system dependent.

The number of shader units is 1536 for the NVIDIA part, versus 320 for the AMD part. Texture units: 96 vs 20. Render output units: 64 vs 8. Pixel fill rate: 72.13 GPixel/s for the GTX 980M, 6.84 GPixel/s for the R6 M255DX. Texture fill rate: 108.2 GTexel/s vs 17.10 GTexel/s. FP32 compute: 3.462 TFLOPS vs 547.2 GFLOPS. These are all categories where the GTX 980M has a clear advantage.

The form factor and power are also different. The GTX 980M is an MXM Module (MXM-B 3.0) with no power connectors. The Radeon R6 M255DX is IGP, also with no power connectors. Display outputs are portable device dependent for both.

The API support is similar but not identical: The GTX 980M supports DirectX 12 (12_1), OpenGL 4.6, and Vulkan 1.4. The Radeon supports DirectX 12 (11_1), OpenGL 4.6, Vulkan 1.2.170. NVIDIA is on a newer Vulkan standard.

Architecture Differences

The architectural split is as deep as the specification split. The NVIDIA chip is a member of the Maxwell 2.0 family, a second-generation design. The AMD chip is GCN 1.0, the original Graphics Core Next architecture. This generational gap is visible in the allocations of resources: the NVIDIA chip has 1,536 shader units, 96 texture mapping units, and 64 ROPs. The AMD chip has 320 shader units, 20 TMUs, and 8 ROPs.

The NVIDIA chip also uses 5.2 billion transistors on a 398mm² die, while the smaller AMD chip uses 690 million transistors on 56mm². The NVIDIA chip has almost twice the transistor density (13.1M vs 12.3M per mm²). This indicates a more advanced design, since it packs more complexity into a similar process node.

The memory subsystem is a key difference. The GTX 980M uses 8GB of GDDR5 memory on a 256-bit interface, with an effective 5Gbps to get 160.4GB/s of bandwidth. The AMD part uses shared system memory, making its bandwidth dependent on the laptop's own memory. For gaming, the dedicated VRAM of the GTX 980M is much better.

The Verdict

Based on the recorded data, the NVIDIA GeForce GTX 980M is the clear pick. It wins the only head-to-head benchmark by a massive 263.7% margin. It has 4.8 times the shader processors, 48 times the texture units, 8 times the ROPs, and a dedicated 8GB GDDR5 memory subsystem with 160.4GB/s of bandwidth. The AMD Radeon R6 M255DX is a low-end part designed for basic tasks; the numbers show that it is more aligned with older GeForce parts like the GTX 560M, 940MX, and GTS 450 than with a modern high-end mobile GPU.

If the laptop is essentially a media consumption, light work machine, and the task is not GPU-limited, the R6 M255DX could be acceptable because its system-shared memory keeps costs and power down. But for any serious gaming, content creation, or compute work, the GeForce GTX 980M is the only option of the two. Its benchmark results put it in a completely different performance class, and the database shows it is 31st percentile, while the R6 M255DX is 28th. The performance gap is not close, it is a chasm, and the GTX 980M is the chip that bridges it.