Intel Iris Pro Graphics P6300 vs NVIDIA GeForce 840M Comparison

Intel Iris Pro Graphics P6300 and NVIDIA GeForce 840M represent two very different approaches to mobile graphics from the same era, and the data shows they end up in a near-dead heat in raw compute. The Iris Pro P6300 is an integrated solution built on Intel's Broadwell GT3e chip, while the 840M is a discrete part from NVIDIA's Maxwell family. Both are end-of-life products now, but understanding where each still makes sense requires looking beyond the headline score.

Where Each One Wins

The benchmark data gives the NVIDIA GeForce 840M a single head-to-head victory, but the margin is razor-thin. In the Geekbench OpenCL test, the 840M scores 5764 against the Iris Pro P6300's 5712, a delta of just -0.9% from the Intel part's perspective. That is effectively a statistical tie, and it means neither card has a decisive advantage in general-purpose compute workloads. The 840M wins the only direct comparison, but the difference is so small that real-world applications would be unlikely to show a consistent winner.

The Intel Iris Pro P6300, however, holds its own in a different way. Its average benchmark score of 5712 places it at the 33rd percentile of all GPUs, while the 840M's average of 5322 sits at the 31st percentile. This is an important distinction: the 840M's single OpenCL result is higher, but its average across all benchmarks (including its Vulkan score of 4880) drags it down. The Iris Pro P6300 has a more consistent performance profile, with only one benchmark result to its name. For users who care about predictable performance across a variety of tasks, the Intel part looks more stable. For users who specifically need the highest peak OpenCL number, the 840M edges ahead.

The 840M also offers a Vulkan score of 4880, a feature the Iris Pro P6300 completely lacks in the benchmark data. This gives the NVIDIA part an advantage in modern API workloads, even if its OpenCL lead is negligible. The Iris Pro P6300 counters with a higher percentile ranking, suggesting that its single strong score places it better relative to the broader GPU landscape than the 840M's mixed results.

FAQ

Q: Which GPU has the higher peak benchmark score?

A: The NVIDIA GeForce 840M scores 5764 in Geekbench OpenCL, while the Intel Iris Pro P6300 scores 5712. The 840M wins this specific test by 0.9%.

Q: Does the Intel Iris Pro P6300 support Vulkan?

A: Yes, the Iris Pro P6300 lists Vulkan 1.0 support in its API specifications, but no Vulkan benchmark score is recorded for it. The GeForce 840M has a recorded Vulkan score of 4880.

Q: How do their average benchmark scores compare?

A: The Intel Iris Pro P6300 has an average benchmark score of 5712, placing it at the 33rd percentile. The NVIDIA GeForce 840M averages 5322, placing it at the 31st percentile.

Q: Which GPU has the higher pixel fill rate?

A: The NVIDIA GeForce 840M achieves 8.992 GPixel/s, which is nearly double the Iris Pro P6300's 4.800 GPixel/s.

Q: Which GPU has more texture mapping units?

A: The Intel Iris Pro P6300 has 48 TMUs, while the NVIDIA GeForce 840M has only 16. This gives the Intel part a 3x advantage in texture units.

Q: What is the memory configuration difference?

A: The GeForce 840M has 2 GB of dedicated DDR3 memory on a 64-bit bus with 16.02 GB/s bandwidth. The Iris Pro P6300 uses system-shared memory with system-dependent bandwidth.

Head-to-Head Benchmarks

The only direct head-to-head benchmark available is Geekbench OpenCL, and the results are remarkably close. The NVIDIA GeForce 840M scores 5764, while the Intel Iris Pro P6300 scores 5712. The delta is -0.9% from the Intel side, meaning the NVIDIA part is ahead by less than one percent. In practical terms, this is within run-to-run variance for most benchmark suites. A user would not notice the difference in everyday tasks, and even compute-heavy workloads would likely be decided by drivers or thermal conditions rather than raw silicon capability.

The 840M's additional Vulkan score of 4880 provides another data point, but there is no equivalent for the Iris Pro P6300 to compare against. This makes it impossible to declare a winner in that API, though the existence of the score suggests the NVIDIA part has working Vulkan drivers that produce measurable results. The Intel part lists Vulkan 1.0 support but no benchmark result, leaving its real-world Vulkan performance unknown.

Looking at the broader rival landscape, both GPUs sit in a crowded mid-range field. The Iris Pro P6300's nearest rivals include the GTX 670MX (5721, -0.1% delta), GTX 550 Ti (5731, -0.3%), and HD 8790M (5691, +0.4%). The 840M's rivals include the 930A (5317, +0.1%), GTX 980M (5308, +0.3%), and 940M (5284, +0.7%). Notably, the 840M's average score of 5322 is actually lower than the Iris Pro P6300's average of 5712, despite the 840M winning the individual OpenCL test. This suggests the 840M's Vulkan result pulls its average down, while the Intel part benefits from having no additional benchmarks to dilute its score.

Specification Differences

The two GPUs differ significantly in their memory and clock configurations. The GeForce 840M runs at a base clock of 1029 MHz with a boost of 1124 MHz, while the Iris Pro P6300 operates at just 300 MHz base and 800 MHz boost. This is a massive clock speed advantage for the NVIDIA part, nearly 3.4x at base and 1.4x at boost. However, the Intel part compensates with 48 texture mapping units versus the 840M's 16, giving it a 3x advantage in texture throughput. The 840M counters with 8 ROPs versus the Intel part's 6, and its pixel rate of 8.992 GPixel/s is almost double the 4.800 GPixel/s of the Iris Pro P6300.

Memory is another clear differentiator. The 840M has 2 GB of dedicated DDR3 memory on a 64-bit bus, delivering 16.02 GB/s of bandwidth. The Iris Pro P6300 uses system-shared memory with system-dependent bandwidth, meaning its performance scales with the host system's RAM configuration. For gaming, dedicated memory is generally preferable, but for compute workloads that benefit from large memory pools, the shared approach can be flexible.

The FP32 compute figures tell a nuanced story. The 840M delivers 863.2 GFLOPS, while the Iris Pro P6300 delivers 614.4 GFLOPS — a 40% advantage for the NVIDIA part. Yet the OpenCL benchmark scores are nearly identical, suggesting that the Intel architecture extracts more real-world compute efficiency from its lower theoretical peak. The texture rate also favors Intel at 38.40 GTexel/s versus 17.98 GTexel/s, a 2.1x difference.

Architecture Differences

The architectural divide is stark. The Iris Pro P6300 is built on Intel's Broadwell GT3e chip using a 14 nm process at Intel's foundry. It belongs to the HD Graphics-W (Broadwell) generation and uses Generation 8.0 architecture. The 840M is a completely different beast: it uses the GM108S chip on TSMC's 28 nm process, with NVIDIA's Maxwell architecture. The 840M has 1,020 million transistors packed into a 77 mm² die, giving it a transistor density of 13.2M per mm². The Intel part has no listed transistor count or die size.

Both GPUs have 384 shading units, but the similarities end there. The Intel part uses a Ring Bus interface, while the 840M uses PCIe 3.0 x8. The 840M has no power connectors and a TDP of 33 W, while the Iris Pro P6300 sips just 15 W — less than half the power draw. This makes the Intel part far more suitable for thin-and-light notebooks, while the 840M requires more thermal headroom. Display outputs are motherboard-dependent for the Intel part and portable-device-dependent for the NVIDIA part, reflecting their different integration levels.

API support differs as well. The Intel part supports DirectX 12 (11_1), OpenGL 4.4, and Vulkan 1.0. The 840M supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.4. The NVIDIA part has more modern API versions, particularly in OpenGL and Vulkan, which could matter for compatibility with newer software. The 840M's predecessor is the GeForce 700M and its successor is the GeForce 900M, while the Intel part has no listed predecessor or successor.

The Verdict

The data paints a picture of two GPUs that are functionally equivalent in compute performance but wildly different in implementation. The NVIDIA GeForce 840M wins the only head-to-head benchmark by 0.9%, which is negligible. It offers a higher peak OpenCL score, a Vulkan score, more than double the pixel rate, 40% more FP32 compute, and dedicated memory with known bandwidth. However, it does all this at 33 W TDP, more than double the Intel part's 15 W.

The Intel Iris Pro P6300 counters with a higher percentile ranking (33rd vs 31st), a 3x advantage in texture units, a 2.1x advantage in texture rate, and dramatically lower power consumption. Its system-shared memory is a limitation, but for users who prioritize battery life and have fast system RAM, it can be a viable choice.

For gaming or applications that need dedicated VRAM and consistent memory bandwidth, the GeForce 840M is the clear pick. Its higher pixel rate and dedicated 2 GB memory make it better suited for rendering workloads. For users who need texture-heavy compute or operate in power-constrained environments, the Iris Pro P6300's 48 TMUs and 15 W TDP are compelling. The 840M's Vulkan 1.4 support makes it more future-proof for modern APIs, while the Intel part's OpenGL 4.4 is dated.

Ultimately, the 840M edges out the Intel part in peak performance and API support, but the Iris Pro P6300 offers better efficiency and stronger texture throughput. If you have the thermal budget, take the 840M. If power efficiency is paramount, the Iris Pro P6300 is the more rational choice. The 0.9% OpenCL delta is not worth making a decision on either way.