AMD Radeon R5 M420 vs NVIDIA Quadro P400 Comparison

The NVIDIA Quadro P400 wins this matchup, and the recorded data makes the call straightforward. In the one direct head-to-head benchmark shared by both cards, Geekbench OpenCL, the Quadro P400 scores 4249 against the Radeon R5 M420's 3956, a lead of roughly seven percent. That single recorded win, combined with a higher database-wide standing (27th percentile versus 23rd), gives the Pascal-based workstation card the overall edge. The Radeon R5 M420 counters with twice the memory capacity, four gigabytes of DDR3 against the P400's two gigabytes of GDDR5, which matters in a narrow set of scenarios. But on compute throughput, feature support, and output capability, the Quadro P400 is the stronger product in the database.

Where Each One Wins

The Quadro P400 wins wherever raw compute and modern API support matter. Its average benchmark score of 4684 places it alongside rivals such as the AMD Radeon R8 M445DX (4727), the NVIDIA GeForce GTX 970M (4628), and the AMD Radeon RX 9060 XT 16 GB (4657), all of which sit within about one percent of its average. In practical terms, the P400 trades blows with hardware a class above the M420's competitive set.

The Radeon R5 M420 wins in exactly one area: memory capacity. Its four gigabytes of DDR3 doubles the P400's two gigabytes of GDDR5. Workloads or games that genuinely require more video memory to avoid spilling into system RAM could favor the M420 on paper, though its slow memory subsystem, just 16.00 GB/s of bandwidth against the P400's 32.06 GB/s, undercuts that advantage in practice. The M420's average score of 3956 puts it statistically level with the NVIDIA GeForce 830M (3957), the NVIDIA GeForce GT 745M (3953), and the NVIDIA Quadro K2000 (3964), all within a fraction of a percent, and just behind the AMD Radeon HD 6850 X2 (3977).

There is also a platform distinction. The M420 is an integrated-class part (IGP slot width) designed for portable devices with display output described as portable-device-dependent. The P400 is a discrete single-slot card with three mini-DisplayPort 1.4a outputs on a full PCIe 3.0 x16 interface. For any fixed workstation deployment, the P400 is the only one of the two that functions as a self-sufficient display adapter.

Architecture Differences

The two cards come from different technological eras. The Quadro P400 is built on the Pascal architecture, specifically the GP107 chip, fabricated on a 14 nm process at Samsung. It packs 3,300 million transistors onto a 132 mm² die, for a transistor density of 25.0 million per square millimeter. The Radeon R5 M420 uses the much older GCN 1.0 architecture on the Jet chip, produced on TSMC's 28 nm node. It contains just 690 million transistors on a 56 mm² die, a density of 12.3 million per square millimeter. The P400's node advantage is more than double the density, and it shows up across every performance metric in the database.

The interesting architectural wrinkle is core count. The M420 actually has more shading units, 320 versus 256, and more texture mapping units, 20 versus 16. Yet it loses on performance because those cores run far slower and sit behind a weaker memory subsystem. The P400 boosts to 1252 MHz against the M420's 850 MHz, and its GDDR5 memory running at an effective 4 Gbps delivers double the bandwidth of the M420's DDR3 at an effective 2 Gbps.

Feature support also favors the Pascal card. The P400 supports DirectX 12 at the 12_1 feature level, while the M420 stops at 11_1 despite also nominally supporting DirectX 12. Vulkan support is 1.4 on the P400 versus 1.2.170 on the M420. Both support OpenGL 4.6. Neither card has RT cores or tensor cores, so ray tracing and dedicated machine learning acceleration are absent from both.

Precision throughput splits further along architectural lines. The P400 delivers 641.0 GFLOPS of FP32 with a severely throttled FP16 rate of 10.02 GFLOPS (a 1:64 ratio). The M420 posts 544.0 GFLOPS FP32 with no FP16 figure recorded in the database.

Head-to-Head Benchmarks

Only one test appears in the database for both cards: Geekbench OpenCL. The Quadro P400 scored 4249; the Radeon R5 M420 scored 3956. That is a 7.4 percent victory for the NVIDIA card. It is not a landslide, but it is consistent with every structural indicator: a denser node, double the memory bandwidth, and higher clock speeds.

The P400 also holds a second recorded result that the M420 lacks entirely: a Geekbench Vulkan score of 5119. That figure is notable on its own, sitting above the card's own OpenCL result and above its average benchmark score of 4684. It suggests the Pascal driver stack extracts more from the modern Vulkan API than from OpenCL. The M420 has no comparable Vulkan data recorded, so cross-API comparison for the AMD card is not possible from the database.

Averages tell the fuller story. The P400's 4684 average places it in the 27th percentile of all GPUs in the database. The M420's 3956 average leaves it in the 23rd percentile. The gap between the two rivals' nearest-competitor sets is instructive: the P400's toughest listed rival, the R8 M445DX, is only 0.9 percent ahead of it, while the M420's nearest match, the GeForce 830M, is effectively identical in score. The P400 competes in a faster neighborhood and still holds its own.

Specification Differences

The specifications diverge on nearly every field. Process node: 14 nm (Samsung) for the P400 versus 28 nm (TSMC) for the M420. Transistors: 3,300 million versus 690 million. Die size: 132 mm² versus 56 mm². Density: 25.0 versus 12.3 million transistors per square millimeter.

Clocks: the P400 runs a 1228 MHz base and 1252 MHz boost; the M420 runs 780 MHz base and 850 MHz boost. Memory: 2 GB GDDR5 at 32.06 GB/s on a 64-bit bus versus 4 GB DDR3 at 16.00 GB/s on the same 64-bit bus width.

Rasterization output is lopsided: the P400 has 16 ROPs producing 20.03 GPixel/s, while the M420 has 8 ROPs producing 6.800 GPixel/s, nearly a threefold advantage in pixel fill rate for the NVIDIA card. Texture rate is closer: 20.03 GTexel/s versus 17.00 GTexel/s, reflecting the M420's extra TMUs. FP32 compute: 641.0 versus 544.0 GFLOPS.

Power and physical specs: the P400 has a 30 W TDP, single-slot width, no power connectors, and a suggested 200 W PSU. The M420 records no TDP, no power connectors, and no suggested PSU, consistent with its IGP classification. Bus interface is PCIe 3.0 x16 for the P400 versus PCIe 3.0 x8 for the M420. Display outputs are three mini-DisplayPort 1.4a connectors versus portable-device-dependent. The P400 measures 150 mm long and 69 mm tall; the M420 has no physical dimensions recorded.

Both are end-of-life products. The P400 shipped on 2017-02-06 within the Quadro Pascal generation, between the Quadro Maxwell predecessor and Quadro Volta successor. The M420 shipped on 2016-05-14 in the Gem System generation, between the Solar System predecessor and Polaris Mobile successor. Neither has a launch MSRP recorded in the database.

FAQ

Q: Which card is faster overall?

A: The Quadro P400. It wins the shared Geekbench OpenCL test 4249 to 3956 (a 7.4 percent margin), holds a higher average score (4684 versus 3956), and ranks in the 27th percentile of all GPUs versus the M420's 23rd.

Q: Which card has more memory?

A: The Radeon R5 M420, with 4 GB of DDR3. The Quadro P400 has 2 GB of GDDR5. However, the P400's memory bandwidth is 32.06 GB/s, double the M420's 16.00 GB/s.

Q: Do either of these cards support ray tracing or AI acceleration?

A: No. Neither card has RT cores or tensor cores recorded in the database.

Q: Which card has better API support?

A: The Quadro P400. It supports DirectX 12 at feature level 12_1 and Vulkan 1.4, versus 11_1 and Vulkan 1.2.170 on the M420. Both support OpenGL 4.6.

Q: Can the Radeon R5 M420 drive three displays from fixed outputs?

A: No. Its display output is listed as portable-device-dependent. The Quadro P400 offers three mini-DisplayPort 1.4a outputs.

Q: Which card has more shading units?

A: The Radeon R5 M420, with 320 shading units versus 256 on the P400. Despite the higher count, its lower clocks and bandwidth leave it behind in measured performance.

The Verdict

Choose the Quadro P400 in nearly every scenario the database can evaluate. It is faster in the one direct benchmark comparison, it competes against stronger rivals (the GTX 970M and R8 M445DX set) while the M420 sits level with the GeForce 830M tier, and it offers roughly triple the pixel fill rate, double the memory bandwidth, a denser 14 nm process, and broader modern API support. As a discrete single-slot card with three DisplayPort outputs and a modest 30 W TDP requiring no auxiliary power connectors, it fits workstation roles the integrated-class M420 simply cannot fill.

Choose the Radeon R5 M420 only where its two structural advantages apply: double the memory capacity for workloads that genuinely need more than 2 GB, and an integrated form factor for portable systems where a discrete card is not an option. Within its own class it holds its ground, scoring within a fraction of a percent of the GeForce 830M, GT 745M, and Quadro K2000. But the database is clear: when both are options, the recorded numbers favor the Quadro P400.