NVIDIA GeForce 840M vs NVIDIA RTX A400 Comparison

The NVIDIA RTX A400 wins this comparison decisively. The recorded head-to-head data shows the A400 leading in every shared benchmark, with margins that go far beyond ordinary generational refreshes: 296 percent ahead in Geekbench OpenCL and 356 percent in Geekbench Vulkan. The GeForce 840M, a Maxwell-era integrated laptop GPU from 2014, simply has no answer to a modern Ampere workstation card. The only domain where the 840M holds an advantage is power draw, at a lower thermal envelope than the A400, and that single qualitative edge cannot offset a roughly fourfold deficit in measured performance.

Where Each One Wins

The RTX A400 wins everywhere performance matters. Its average benchmark score of 6078 places it in the 35th percentile of all GPUs in the database, and its closest rivals by average score are the GeForce MX230 (6077), the Quadro P2000 (6049), the Iris Pro Graphics 6200 (6117), and the Radeon 760M (6019). In other words, it sits in a cluster of entry-level dedicated graphics, trading blows with all of them within a single percentage point.

The GeForce 840M, with an average score of 5322 and a percentile ranking of 31, also has a defined rival set: the GeForce 930A (5317), the GTX 980M (5308), the Radeon R7 M445 (5358), and the GeForce 940M (5284). Notably, its average score trails the A400's by about 14 percent, but the shared compute benchmarks reveal the real gap, because the average score blends incompatible test sets. Where the two cards were measured on identical workloads, the A400 is roughly four times faster.

The 840M's genuine win is efficiency in a narrow sense: a 33 W thermal design point versus 50 W for the A400. It is also an integrated-format part requiring no slot and no power connectors, which made it suitable for thin laptops of its era. That is the extent of its case. For any compute, graphics, or workstation task recorded in the database, the A400 is the only rational choice between the two.

Architecture Differences

The two GPUs are separated by a decade of NVIDIA architecture and three major process-node transitions. The RTX A400 is built on the Ampere architecture, specifically the GA107 chip, fabricated at Samsung on an 8 nm process. It packs 8,700 million transistors into a 200 mm² die, a density of 43.5 million transistors per square millimeter. The GeForce 840M uses the Maxwell architecture, chip GM108S, fabricated at TSMC on a 28 nm process, with 1,020 million transistors on a 77 mm² die and a density of 13.2 million transistors per square millimeter.

That density gap translates directly into the resource counts. The A400 fields 768 shading units, 24 texture mapping units, 16 render outputs, 6 RT cores, and 24 tensor cores. The 840M has half the shader count at 384, 16 TMUs, 8 ROPs, and no RT or tensor hardware at all. Ray tracing and hardware-accelerated matrix workloads are capabilities the older part simply lacks.

Clocks also favor the A400: a base of 1417 MHz and a boost of 1762 MHz, against 1029 MHz base and 1124 MHz boost for the 840M. The theoretical output figures follow. The A400 delivers 2.706 TFLOPS of FP32, a pixel rate of 28.19 GPixel/s, and a texture rate of 42.29 GTexel/s. The 840M manages 863.2 GFLOPS, 8.992 GPixel/s, and 17.98 GTexel/s. The A400 also supports FP16 at a 1:1 ratio with FP32; the 840M lists no FP16 capability.

Memory is another categorical difference. The A400 carries 4 GB of GDDR6 on a 64-bit bus, clocked at 1500 MHz (12 Gbps effective) for 96.00 GB/s of bandwidth. The 840M has 2 GB of DDR3 on the same 64-bit bus width, running at 1001 MHz (2 Gbps effective) for just 16.02 GB/s. Six times the memory bandwidth and double the capacity, with a far faster memory type, means the A400 can feed its shader array while the 840M starves.

Feature support diverges as well. The A400 targets DirectX 12 Ultimate (feature level 12_2), while the 840M stops at DirectX 12 with feature level 11_0. Both report OpenGL 4.6 and Vulkan 1.4 in the database. The A400 connects over PCIe 4.0 x8 and offers four mini-DisplayPort 1.4a outputs, a workstation-class display configuration. The 840M uses PCIe 3.0 x8 and has portable-device-dependent outputs, as befits an integrated laptop part.

Production status seals the contrast: the A400 is an active product released on April 15, 2024, sitting between the Quadro Turing generation it follows and the Workstation Ada generation that succeeds it. The 840M is end-of-life hardware introduced on March 11, 2014, part of the GeForce 800M line between the 700M and 900M series.

Head-to-Head Benchmarks

Only two tests cover both cards, and both are landslides.

In Geekbench OpenCL, the RTX A400 scored 22844 against the GeForce 840M's 5764. That is a 296 percent advantage, meaning the A400 delivers nearly four times the OpenCL compute throughput. For any general-purpose GPU workload that rides on OpenCL, from physics simulation to image processing, the 840M is not in the same performance class.

Geekbench Vulkan is even more lopsided: 22237 for the A400 versus 4880 for the 840M, a 356 percent gap. The Vulkan result approaching the OpenCL result on the A400 indicates a well-balanced modern driver stack, while the 840M's Vulkan score falling below its OpenCL score shows the older architecture struggling to exploit the newer API.

The A400's individual results fill out the picture. Its Passmark G3D score of 5983, Passmark GPU compute score of 2557, and Passmark 2D score of 899 sit alongside a spread of DirectCompute-era Passmark DirectX results: 87 in DirectX 9, 32 in DirectX 10, 37 in DirectX 11, and 27 in DirectX 12. The database records no Passmark results for the 840M, so the comparison rests on the two Geekbench suites, both of which the A400 sweeps.

Contextualizing against rivals, the A400's performance cluster (MX230, Quadro P2000, Iris Pro 6200, Radeon 760M) represents usable entry-level dedicated graphics. The 840M's cluster (930A, GTX 980M by average score, R7 M445, 940M) reflects its vintage, and its average score of 5322 lands at the 31st percentile versus the A400's 35th.

The Verdict

Choose the RTX A400 for anything measured here: compute, Vulkan workloads, multi-display professional use, ray tracing, or modern API features. It is an active, current-generation workstation product with DX12 Ultimate support, tensor and RT hardware, 4 GB of fast GDDR6, and four mini-DisplayPort outputs. It fits a single slot, needs no auxiliary power connectors, carries a 50 W rating, and needs only a modest system power supply per the recorded suggestion.

The GeForce 840M is a historical artifact. It was designed for thin notebooks where its 33 W envelope and integrated format mattered, and for that context a decade ago it was a reasonable fit. Today it is end-of-life, limited to 2 GB of slow DDR3, feature level 11_0, and compute throughput roughly a quarter of the A400's. The data supports exactly one conclusion: between these two, the RTX A400 wins every shared benchmark and every specification comparison that affects performance.

FAQ

Q: How much faster is the RTX A400 than the GeForce 840M in compute?

A: In Geekbench OpenCL the A400 scored 22844 versus 5764, a 296 percent lead. In Geekbench Vulkan it scored 22237 versus 4880, a 356 percent lead.

Q: Does the GeForce 840M support ray tracing?

A: No. The Maxwell-based 840M has no RT cores and no tensor cores. The Ampere-based A400 has 6 RT cores and 24 tensor cores.

Q: How do the memory configurations compare?

A: The A400 has 4 GB of GDDR6 on a 64-bit bus with 96.00 GB/s of bandwidth. The 840M has 2 GB of DDR3 on a 64-bit bus with 16.02 GB/s of bandwidth.

Q: Which card uses less power?

A: The 840M, with a 33 W rating versus 50 W for the A400. Neither requires power connectors; the A400 is single-slot with a suggested system supply of 250 W.

Q: Are both cards still in production?

A: No. The RTX A400 is active and was released on April 15, 2024. The GeForce 840M is end-of-life, released on March 11, 2014.

Q: Which GPUs are closest in performance to each card?

A: The A400 matches the GeForce MX230, Quadro P2000, Iris Pro Graphics 6200, and Radeon 760M within about one percent on average score. The 840M groups with the GeForce 930A, GTX 980M, Radeon R7 M445, and GeForce 940M.

Specification Differences

• Architecture: Ampere (A400) versus Maxwell (840M)
• Chip: GA107 versus GM108S
• Process node: 8 nm at Samsung versus 28 nm at TSMC
• Transistors: 8,700 million versus 1,020 million
• Die size and density: 200 mm² at 43.5M/mm² versus 77 mm² at 13.2M/mm²
• Shading units: 768 versus 384
• TMUs: 24 versus 16
• ROPs: 16 versus 8
• RT cores: 6 versus none
• Tensor cores: 24 versus none
• Base clock: 1417 MHz versus 1029 MHz
• Boost clock: 1762 MHz versus 1124 MHz
• Memory: 4 GB GDDR6 at 1500 MHz (12 Gbps effective), 96.00 GB/s versus 2 GB DDR3 at 1001 MHz (2 Gbps effective), 16.02 GB/s
• Bus width: 64 bit on both, but interface differs: PCIe 4.0 x8 versus PCIe 3.0 x8
• FP32 throughput: 2.706 TFLOPS versus 863.2 GFLOPS
• FP16: 2.706 TFLOPS (1:1) versus not available
• Pixel rate: 28.19 GPixel/s versus 8.992 GPixel/s
• Texture rate: 42.29 GTexel/s versus 17.98 GTexel/s
• TDP: 50 W versus 33 W
• Slot width: Single-slot versus IGP
• Display outputs: 4x mini-DisplayPort 1.4a versus portable-device-dependent
• DirectX support: 12 Ultimate (12_2) versus 12 (11_0)
• Release date: April 15, 2024 versus March 11, 2014
• Production status: Active versus end-of-life
• Form factor: 163 mm length, 69 mm height versus integrated, no listed dimensions