Intel Iris Pro Graphics P580 vs NVIDIA GeForce GT 555M Comparison

Intel Iris Pro Graphics P580 and NVIDIA GeForce GT 555M are both end-of-life mobile graphics solutions, but they come from different eras and design philosophies. The Intel part is an integrated processor graphics unit built on a 14 nm+ process, while the NVIDIA chip is a discrete Fermi-architecture part from 2011 built on 40 nm. Benchmark data shows a clear performance gap favoring the Intel solution, though the two share similar overall market positioning.

Head-to-Head Benchmarks

The only direct benchmark comparison available between these two GPUs is Geekbench OpenCL. In that test, the Intel Iris Pro Graphics P580 scores 9082 points, while the NVIDIA GeForce GT 555M scores 6493 points. This represents a 39.9% advantage for the Intel part, which is a substantial margin in raw compute performance.

Looking at the broader benchmark context, the Intel P580’s average benchmark score across all tests is 7170, while the GT 555M’s average is 6493. The Intel part’s average is driven by two scores: 9082 in OpenCL and 5258 in Vulkan. The NVIDIA part only has one recorded benchmark result, the 6493 OpenCL score, so its average equals that single number.

The percentile rankings place both GPUs in the lower-midrange of all GPUs. The Intel P580 sits at the 39th percentile, while the GT 555M sits at the 37th percentile. Despite the 39.9% head-to-head win in OpenCL, their overall percentile positions are only two points apart, suggesting that the Intel advantage is concentrated in compute workloads rather than representing a fundamentally different performance tier.

When examining the Intel P580’s nearest rivals, the data shows it performs almost identically to the NVIDIA GeForce GTX 560 SE (0% delta, 7171 vs 7170), the NVIDIA GeForce GTX 970 (0.2% ahead, 7157 vs 7170), and the AMD Radeon Vega 8 Mobile (0.5% behind, 7203 vs 7170). This clustering indicates the P580’s average score places it in a crowded performance band where many GPUs are within 1% of each other.

For the GT 555M, its nearest rivals include the NVIDIA Quadro M5000M (0.2% behind at 6481 vs 6493), the AMD Radeon Vega 10 Mobile (0.3% ahead at 6476 vs 6493), and the NVIDIA GeForce GTX 670M (0.3% behind at 6513 vs 6493). The tight grouping around 6493 confirms the GT 555M is a solidly mid-pack performer for its generation, but the P580’s 39.9% lead in the head-to-head test is decisive.

The Verdict

Based strictly on the benchmark data, the Intel Iris Pro Graphics P580 is the faster GPU. It wins the only direct head-to-head comparison by 39.9%, and its average benchmark score of 7170 exceeds the GT 555M’s 6493 by 677 points. The Intel part also has a higher percentile ranking at 39 versus 37.

The GT 555M’s only benchmark result, 6493 in OpenCL, is substantially lower than the P580’s 9082 in the same test. This is not a marginal difference — it is a clear generational and architectural gap. The P580’s Vulkan score of 5258 is also respectable, though it is lower than its OpenCL score, indicating the architecture performs better in OpenCL workloads.

For users choosing between these two, the data points decisively to the Intel P580 for any compute-oriented tasks. The GT 555M might still be relevant in systems where it is the only option, but from a pure performance standpoint, the Intel part wins every measured category. The P580 also offers Vulkan support, which the GT 555M lacks entirely, making the Intel part more future-proof for modern graphics APIs.

Architecture Differences

The Intel Iris Pro Graphics P580 is built on the Skylake GT4e chip using Intel’s Generation 9.0 architecture, fabricated on a 14 nm+ process at Intel’s own foundry. The GT 555M uses NVIDIA’s GF106 chip based on the Fermi architecture, manufactured by TSMC on a 40 nm process. The process node difference is significant: 14 nm+ versus 40 nm means the Intel part has a much denser, more power-efficient transistor layout.

The Intel chip features 576 shading units, 72 texture mapping units, and 9 raster output pipelines. In contrast, the NVIDIA chip has 144 shading units, 24 TMUs, and 16 ROPs. The Intel part has four times the shading units and three times the TMUs, though the NVIDIA chip has more ROPs. These differences translate directly to compute throughput: the P580 delivers 1,152.0 GFLOPS of FP32 performance and 2.304 TFLOPS of FP16 (2:1 ratio), while the GT 555M manages only 339.8 GFLOPS FP32 with no FP16 support listed.

Memory configurations are fundamentally different. The P580 uses system-shared memory with a system-dependent bandwidth, meaning it relies on the host system’s RAM. The GT 555M has dedicated 1024 MB of DDR3 memory on a 128-bit bus, delivering 28.80 GB/s of bandwidth. The NVIDIA part’s dedicated memory is a structural advantage for certain workloads, but the P580’s much higher compute throughput appears to compensate in the benchmark results.

The Intel part is an IGP with a Ring Bus interface and motherboard-dependent display outputs, while the GT 555M is a discrete chip using PCIe 2.0 x16 with portable-device-dependent outputs. Power consumption also differs: the P580 has a 15 W TDP, while the GT 555M draws 35 W. The Intel part achieves higher performance at lower power, a direct consequence of the newer process node and integrated design.

API support shows another generational gap. The P580 supports DirectX 12 (12_1), OpenGL 4.6, and Vulkan 1.3. The GT 555M supports DirectX 12 (11_0) and OpenGL 4.6 but has no Vulkan support. The Intel part also reports a transistor count of 1,170 million for the GT 555M and a die size of 238 mm², while the P580’s transistor and die size data are not provided.

FAQ

Q: Which GPU has a higher Geekbench OpenCL score?

A: The Intel Iris Pro Graphics P580 scores 9082, which is 39.9% higher than the NVIDIA GeForce GT 555M’s 6493.

Q: Does the NVIDIA GeForce GT 555M support Vulkan?

A: No, the GT 555M’s API list includes DirectX 12 (11_0) and OpenGL 4.6 but no Vulkan support. The Intel P580 supports Vulkan 1.3.

Q: What are the shading unit counts for each GPU?

A: The Intel P580 has 576 shading units, while the NVIDIA GT 555M has 144 shading units.

Q: How do their power consumptions compare?

A: The Intel P580 has a TDP of 15 W, while the NVIDIA GT 555M has a TDP of 35 W.

Q: Which GPU has a higher average benchmark score?

A: The Intel P580 has an average benchmark score of 7170, compared to the GT 555M’s 6493.

Q: What memory configuration does each GPU use?

A: The Intel P580 uses system-shared memory with system-dependent bandwidth, while the GT 555M has 1024 MB of dedicated DDR3 memory with 28.80 GB/s bandwidth on a 128-bit bus.

Where Each One Wins

The Intel Iris Pro Graphics P580 wins in raw compute performance across every measured benchmark. Its OpenCL score of 9082 is 39.9% higher, and its average benchmark score of 7170 is 677 points above the GT 555M. The P580 also offers Vulkan support, a wider feature set for modern APIs, and does so at a lower 15 W TDP. For any workload that stresses shading units, texture throughput, or FP32/FP16 compute, the P580 is the clear choice.

The NVIDIA GeForce GT 555M has specific structural advantages that are not reflected in the benchmark data. It has dedicated 1024 MB of DDR3 memory with a fixed 28.80 GB/s bandwidth, which can be beneficial in scenarios where memory latency and guaranteed bandwidth matter more than raw compute throughput. It also has more ROPs (16 versus 9), which could theoretically help in pixel-heavy workloads, though the benchmark results do not show a scenario where this advantage manifests.

The GT 555M’s PCIe 2.0 x16 interface is a standard discrete GPU connection, while the P580 relies on a Ring Bus and system-shared memory. In systems with slow system RAM, the P580’s performance could degrade, whereas the GT 555M’s dedicated memory is independent of system memory speed. However, the available data shows the P580’s compute advantage is so large that it overcomes any memory-related handicaps in the measured tests.

For users working with OpenCL compute tasks, the P580 is superior by a wide margin. For users needing Vulkan compatibility, the P580 is the only option. For users constrained by power budgets, the P580’s 15 W TDP is more than twice as efficient as the GT 555M’s 35 W. The GT 555M’s only potential edge is in systems where dedicated memory is absolutely required and the host system’s RAM is exceptionally slow.

Specification Differences

The two GPUs differ across nearly every specification category. The Intel P580 uses a 14 nm+ process from Intel, while the GT 555M uses a 40 nm process from TSMC. The GT 555M has listed transistor and die size data (1,170 million transistors, 238 mm², 4.9M / mm² density), while the P580 does not provide these figures.

Clock speeds differ fundamentally: the P580 has a base clock of 350 MHz and a boost clock of 1000 MHz, while the GT 555M has no base or boost clock listed — only a memory clock of 900 MHz (1800 Mbps effective). The P580’s memory clock is listed as "System Shared" with no fixed speed.

Memory specifications are entirely different. The P580 uses system-shared memory with system-dependent bandwidth, while the GT 555M has 1024 MB of DDR3 on a 128-bit bus with 28.80 GB/s bandwidth. The P580’s pixel rate is 9.000 GPixel/s versus the GT 555M’s 3.540 GPixel/s, and the texture rate is 72.00 GTexel/s versus 14.16 GTexel/s.

Compute throughput favors the P580: 1,152.0 GFLOPS FP32 and 2.304 TFLOPS FP16 (2:1), while the GT 555M has 339.8 GFLOPS FP32 and no FP16 data. The P580 has 576 shading units, 72 TMUs, and 9 ROPs, while the GT 555M has 144 shading units, 24 TMUs, and 16 ROPs.

Power and interface also differ: the P580 has a 15 W TDP and Ring Bus interface, while the GT 555M has a 35 W TDP and PCIe 2.0 x16. The P580 supports DirectX 12 (12_1), OpenGL 4.6, and Vulkan 1.3, while the GT 555M supports DirectX 12 (11_0) and OpenGL 4.6 but no Vulkan. The GT 555M lists its predecessor as GeForce 400M and successor as GeForce 600M, while the P580 has no predecessor or successor listed. Both are end-of-life products, with the P580 released on 2015-08-31 and the GT 555M on 2011-07-01.