AMD Radeon R8 M445DX vs NVIDIA Quadro P400 Comparison

The AMD Radeon R8 M445DX and NVIDIA Quadro P400 are both end-of-life, low-profile graphics solutions aimed at very different use cases, yet they land within 1% of each other in average benchmark score. The R8 M445DX is an integrated GPU (IGP) built into AMD's "Gem System Hybrid" platform, while the Quadro P400 is a single-slot, 30-watt discrete adapter with dedicated GDDR5 memory. The benchmark data shows a near-tie in raw compute, but the specifications reveal two entirely different design philosophies.

Where Each One Wins

The head-to-head data gives the AMD Radeon R8 M445DX a single victory in the only shared benchmark test. In Geekbench OpenCL, the R8 M445DX scores 4727 against the Quadro P400's 4249, a delta of 11.2% in AMD's favor. This is the only direct comparison available, and it shows the integrated part pulling ahead by a meaningful margin in this particular compute workload.

The NVIDIA Quadro P400, despite losing the OpenCL test, wins in every other measurable category that matters for professional deployment. It has a dedicated 2 GB GDDR5 frame buffer with 32.06 GB/s of bandwidth, whereas the R8 M445DX relies on "System Shared" memory with bandwidth described as "System Dependent." The P400 also offers three mini-DisplayPort 1.4a outputs and a PCIe 3.0 x16 interface, making it a functional standalone graphics card. The R8 M445DX's display outputs are "Portable Device Dependent," meaning it cannot be deployed outside a specific laptop or hybrid system.

The architectural wins are also lopsided. The Quadro P400 has a 20.03 GPixel/s pixel rate versus the R8 M445DX's 8.168 GPixel/s, a 2.45x advantage in fill-rate-heavy tasks. The P400 also supports DirectX 12_1 and Vulkan 1.4, while the R8 M445DX is limited to DirectX 12_0 and Vulkan 1.2.170. For OpenGL 4.6, both are equal.

FAQ

Q: Which GPU is faster in the Geekbench OpenCL benchmark?

A: The AMD Radeon R8 M445DX scores 4727 versus the NVIDIA Quadro P400's 4249, a difference of 11.2% in AMD's favor.

Q: Does the R8 M445DX have its own video memory?

A: No. The R8 M445DX uses "System Shared" memory for both size and type, with bandwidth labeled "System Dependent." The Quadro P400, by contrast, has 2 GB of GDDR5 on a 64-bit bus with 32.06 GB/s of bandwidth.

Q: Can the R8 M445DX be installed in a desktop PC?

A: No. Its bus interface is listed as "IGP" and its slot width is "IGP," with display outputs described as "Portable Device Dependent." It is an integrated part, not a discrete card.

Q: What are the power requirements for the Quadro P400?

A: The P400 has a 30 W TDP, uses no power connectors, and has a suggested PSU rating of 200 W. It is a single-slot card measuring 150 mm (5.9 inches) in length and 69 mm (2.7 inches) in height.

Q: Which GPU has better API support?

A: The Quadro P400 supports DirectX 12_1 and Vulkan 1.4, while the R8 M445DX is capped at DirectX 12_0 and Vulkan 1.2.170. Both support OpenGL 4.6.

Q: How do these GPUs compare to their nearest rivals?

A: The R8 M445DX sits 0.9% above the Quadro P400 and 0.5% below the AMD Radeon R5 M335. The Quadro P400 sits 0.9% below the R8 M445DX and 1.2% above the NVIDIA GeForce GTX 970M.

Head-to-Head Benchmarks

The only direct benchmark comparison available between these two GPUs is Geekbench OpenCL, and it results in a clear win for the AMD Radeon R8 M445DX. AMD's part scores 4727, while the NVIDIA Quadro P400 scores 4249. The 11.2% delta is substantial in this synthetic compute test, suggesting the R8 M445DX's 320 shading units and 20 texture mapping units provide a raw throughput advantage over the Quadro P400's 256 shading units and 16 TMUs.

This result is interesting because the Quadro P400 has significantly higher clock speeds — a 1228 MHz base and 1252 MHz boost versus the R8 M445DX's 780 MHz base and 1021 MHz boost. The AMD part compensates with 20% more shaders and 25% more TMUs, plus a higher FP32 rating of 653.4 GFLOPS versus 641.0 GFLOPS. The texture rates are nearly identical (20.42 GTexel/s for AMD, 20.03 GTexel/s for NVIDIA), but the pixel rates diverge heavily — the P400's 20.03 GPixel/s dwarfs the R8 M445DX's 8.168 GPixel/s.

The R8 M445DX also has a major FP16 advantage, offering 653.4 GFLOPS at a 1:1 ratio, while the P400 is limited to 10.02 GFLOPS at a 1:64 ratio. However, the P400's dedicated memory and professional display outputs make it the more versatile card in real-world deployments. The Quadro P400 also has a second benchmark result — 5119 in Geekbench Vulkan — which the R8 M445DX does not have, though this cannot be directly compared.

Specification Differences

The two GPUs differ in nearly every physical and memory specification. The AMD Radeon R8 M445DX is built on a 28 nm TSMC process with 1,550 million transistors on a 125 mm² die, giving a transistor density of 12.4M per mm². The NVIDIA Quadro P400 uses a 14 nm Samsung process with 3,300 million transistors on a 132 mm² die, resulting in a density of 25.0M per mm² — more than double the AMD part.

Memory is the most consequential difference. The R8 M445DX has no dedicated VRAM; it uses system memory with a shared bus width and system-dependent bandwidth. The P400 has 2 GB of GDDR5 on a 64-bit bus, running at 1002 MHz (4 Gbps effective) for 32.06 GB/s of bandwidth. The AMD part's memory clock is listed as "System Shared," meaning it is entirely dependent on the host system's RAM configuration.

The compute units also differ: the R8 M445DX has 320 shading units, 20 TMUs, and 8 ROPs, while the P400 has 256 shading units, 16 TMUs, and 16 ROPs. The P400 doubles the ROP count, which explains its much higher pixel rate. The bus interface is IGP for AMD versus PCIe 3.0 x16 for NVIDIA, and the P400 is a single-slot card with no power connectors and a 30 W TDP, while the R8 M445DX has no listed TDP or slot width beyond "IGP."

Architecture Differences

The AMD Radeon R8 M445DX is based on the Meso chip using GCN 3.0 architecture, part of the "Gem System Hybrid (Rx M400)" generation. It is a 28 nm part fabricated by TSMC. The NVIDIA Quadro P400 uses the GP107 chip with Pascal architecture, belonging to the "Quadro Pascal (Px000)" generation, built on Samsung's 14 nm process. Both are end-of-life products, with the AMD releasing on 2016-05-14 and the NVIDIA on 2017-02-06.

The transistor counts reveal a fundamental design difference. The P400 packs 3,300 million transistors into a 132 mm² die, achieving a density of 25.0M per mm². The R8 M445DX has only 1,550 million transistors on a 125 mm² die, for a density of 12.4M per mm². This means the NVIDIA chip is more than twice as dense, which is consistent with its more modern 14 nm process and later release date.

FP16 compute is another major architectural split. The R8 M445DX offers 653.4 GFLOPS at a 1:1 ratio with FP32, while the P400 offers only 10.02 GFLOPS at a 1:64 ratio. This makes the AMD part far more capable in workloads that can utilize half-precision math. However, the P400's Pascal architecture includes support for DirectX 12_1 and Vulkan 1.4, while GCN 3.0 is limited to DirectX 12_0 and Vulkan 1.2.170. Both support OpenGL 4.6.

The Quadro P400 has a predecessor (Quadro Maxwell) and successor (Quadro Volta), while the R8 M445DX lists neither. The P400's display outputs are three mini-DisplayPort 1.4a connectors, while the R8 M445DX's outputs are entirely dependent on the portable device it is integrated into.

The Verdict

The data presents a clear split based on use case. If the requirement is raw compute in a Geekbench OpenCL workload, the AMD Radeon R8 M445DX wins by 11.2%, scoring 4727 against the P400's 4249. It also offers 20% more shading units, 25% more TMUs, and a 65x advantage in FP16 throughput. For any task that can leverage these resources, the AMD part is the better choice.

However, the R8 M445DX is an integrated GPU with system-shared memory and no standalone display outputs. It cannot be purchased, installed, or deployed as a discrete solution. Its performance is entirely dependent on the host system's memory and cooling, and its "Portable Device Dependent" nature means it only exists inside a specific laptop or hybrid platform. The Quadro P400, conversely, is a complete, self-contained graphics card with 2 GB of dedicated GDDR5, a 64-bit memory bus, 32.06 GB/s of bandwidth, and three mini-DisplayPort outputs. It fits in a single slot, draws only 30 W, requires no power connectors, and works with a 200 W PSU.

The Quadro P400 also wins on pixel throughput (20.03 GPixel/s vs 8.168 GPixel/s), ROP count (16 vs 8), API support (DirectX 12_1 and Vulkan 1.4 vs DirectX 12_0 and Vulkan 1.2.170), and overall density (25.0M transistors per mm² vs 12.4M). Its 150 mm length and 69 mm height make it a compact, low-profile option for professional workstations.

For a builder or integrator needing a small, efficient, professional-grade discrete GPU with dedicated memory and standard display outputs, the Quadro P400 is the only viable choice between these two. Its lower OpenCL score is a minor trade-off for the flexibility and reliability of a true standalone card. For someone constrained to a specific AMD hybrid laptop platform, the R8 M445DX is simply what is available, and its 11.2% OpenCL advantage over the P400 is a nice bonus — but it is not a choice, it is a given. The verdict from the data is straightforward: the Quadro P400 is the practical, deployable GPU, while the R8 M445DX is a capable integrated component that wins the one benchmark they share.