Performance to price ratio. The higher, the better.
840A vs GT 640
Price now
158$
Games supported
58%
- Interface PCIe 3.0 x16
- Core clock speed 902 MHz
- Max video memory 2 GB
- Memory type DDR3
- Memory clock speed 1782 MHz
- Maximum resolution
- Interface PCIe 3.0 x8
- Core clock speed 1029 MHz
- Max video memory 2 GB
- Memory type DDR3
- Memory clock speed 2002 MHz
- Maximum resolution
Price now
no data
Games supported
58%
General info
GPU architecture, market segment, value for money and other general parameters compared.
| Place in performance ranking | 674 | 676 |
| Value for money | 0.25 | no data |
| Architecture | Kepler (2012−2018) | Maxwell (2014−2018) |
| GPU code name | GK107 | GM108 |
| Market segment | Desktop | Desktop |
| Release date | 5 June 2012 (11 years old) | 17 March 2014 (9 years old) |
| Launch price (MSRP) | $99 | no data |
| Current price | $158 (1.6x MSRP) | no data |
Value for money
no data
Technical specs
General performance parameters such as number of shaders, GPU core base clock and boost clock speeds, manufacturing process, texturing and calculation speed. These parameters indirectly speak of performance, but for precise assessment you have to consider their benchmark and gaming test results. Note that power consumption of some graphics cards can well exceed their nominal TDP, especially when overclocked.
| Pipelines / CUDA cores | 384 | 384 |
| Core clock speed | 902 MHz | 1029 MHz |
| Boost clock speed | no data | 1124 MHz |
| Number of transistors | 1,270 million | no data |
| Manufacturing process technology | 28 nm | 28 nm |
| Power consumption (TDP) | 65 Watt | 33 Watt |
| Texture fill rate | 28.86 | 17.98 |
| Floating-point performance | 692.7 gflops | 863.2 gflops |
Size and compatibility
Information on compatibility with other computer components. Useful when choosing a future computer configuration or upgrading an existing one. For desktop graphics cards it's interface and bus (motherboard compatibility), additional power connectors (power supply compatibility).
| Interface | PCIe 3.0 x16 | PCIe 3.0 x8 |
| Length | 145 mm | no data |
| Width | 1-slot | IGP |
| Supplementary power connectors | None | no data |
Memory
Parameters of VRAM installed: its type, size, bus, clock and resulting bandwidth. Integrated GPUs have no dedicated VRAM and use a shared part of system RAM.
| Memory type | DDR3 | DDR3 |
| Maximum RAM amount | 2 GB | 2 GB |
| Memory bus width | 128 Bit | 64 Bit |
| Memory clock speed | 1782 MHz | 2002 MHz |
| Memory bandwidth | 28.51 GB/s | 16.02 GB/s |
Video outputs and ports
Types and number of video connectors present on the reviewed GPUs. As a rule, data in this section is precise only for desktop reference ones (so-called Founders Edition for NVIDIA chips). OEM manufacturers may change the number and type of output ports, while for notebook cards availability of certain video outputs ports depends on the laptop model rather than on the card itself.
| Display Connectors | 1x DVI, 1x HDMI, 1x DisplayPort | No outputs |
| HDMI | + | no data |
API support
List of supported graphics and general-purpose computing APIs, including their specific versions.
| DirectX | 12 (11_0) | 12 (11_0) |
| Shader Model | 5.1 | 5.1 |
| OpenGL | 4.6 | 4.6 |
| OpenCL | 1.2 | 1.2 |
| Vulkan | 1.1.126 | 1.1.126 |
| CUDA | 3.0 | 5.0 |
Synthetic benchmark performance
Non-gaming benchmark performance comparison. The combined score is measured on a 0-100 point scale.
Combined synthetic benchmark score
This is our combined benchmark performance score. We are regularly improving our combining algorithms, but if you find some perceived inconsistencies, feel free to speak up in comments section, we usually fix problems quickly.
Passmark
This is probably the most ubiquitous benchmark, part of Passmark PerformanceTest suite. It gives the graphics card a thorough evaluation under various load, providing four separate benchmarks for Direct3D versions 9, 10, 11 and 12 (the last being done in 4K resolution if possible), and few more tests engaging DirectCompute capabilities.
Benchmark coverage: 24%
GeekBench 5 OpenCL
Geekbench 5 is a widespread graphics card benchmark combined from 11 different test scenarios. All these scenarios rely on direct usage of GPU's processing power, no 3D rendering is involved. This variation uses OpenCL API by Khronos Group.
Benchmark coverage: 9%
840A outperforms GT 640 by 52% in GeekBench 5 OpenCL.
Mining hashrates
Cryptocurrency mining performance of GeForce GT 640 and GeForce 840A. Usually measured in megahashes per second.
| Bitcoin / BTC (SHA256) | 24 Mh/s | no data |
Gaming performance
Let's see how good the compared graphics cards are for gaming. Particular gaming benchmark results are measured in FPS.
Advantages and disadvantages
| Performance score | 3.01 | 3.00 |
| Recency | 5 June 2012 | 17 March 2014 |
| Memory bus width | 128 | 64 |
| Memory bandwidth | 28.51 | 16.02 |
| Power consumption (TDP) | 65 Watt | 33 Watt |
We couldn't decide between GeForce GT 640 and GeForce 840A. The differences in performance seem too small.
Should you still have questions concerning choice between the reviewed GPUs, ask them in Comments section, and we shall answer.
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