Select any two GPUs for comparison

Gaming Performance Comparison

Recommended System Requirements
Game GeForce GT 640 Radeon HD 3870 X2
Cyberpunk 2077 653% 631%
Hitman 3 880% 851%
Resident Evil 8 653% 631%
Assassins Creed: Valhalla 589% 569%
FIFA 21 280% 269%
Grand Theft Auto VI 960% 929%
Call of Duty: Black Ops Cold War 567% 547%
Genshin Impact 653% 631%
Far Cry 6 990% 958%
The Medium 840% 813%

In terms of overall gaming performance, the graphical capabilities of the AMD Radeon HD 3870 X2 are marginally better than the Nvidia GeForce GT 640.

The GeForce GT 640 has a 77 MHz higher core clock speed and 16 more Texture Mapping Units than the HD 3870. This results in the GeForce GT 640 providing 15.7 GTexel/s better texturing performance. This still holds weight but shader performance is generally more relevant, particularly since both of these GPUs support at least DirectX 10.

The GeForce GT 640 has a 77 MHz higher core clock speed than the HD 3870 and the same number of Render Output Units. This results in the GeForce GT 640 providing 1.2 GPixel/s better pixeling performance. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

The GeForce GT 640 was released over three years more recently than the HD 3870, and so the GeForce GT 640 is likely to have far better driver support, meaning it will be much more optimized and ultimately superior to the HD 3870 when running the latest games.

The GeForce GT 640 has 1024 MB more video memory than the HD 3870, so is likely to be much better at displaying game textures at higher resolutions. However, overall, the HD 3870 has superior memory performance.

The HD 3870 has 29.1 GB/sec greater memory bandwidth than the GeForce GT 640, which means that the memory performance of the HD 3870 is slightly better than the GeForce GT 640.

The GeForce GT 640 has 384 Shader Processing Units and the Radeon HD 3870 X2 has 640. However, the actual shader performance of the GeForce GT 640 is 346 and the actual shader performance of the HD 3870 is 528. The HD 3870 having 182 better shader performance and an altogether better performance when taking into account other relevant data means that the HD 3870 delivers a marginally smoother and more efficient experience when processing graphical data than the GeForce GT 640.

The GeForce GT 640 transistor size technology is 27 nm (nanometers) smaller than the HD 3870. This means that the GeForce GT 640 is expected to run slightly cooler and achieve higher clock frequencies than the HD 3870. While they exhibit similar graphical performance, the GeForce GT 640 should consume less power than the HD 3870.

The GeForce GT 640 requires 65 Watts to run and the Radeon HD 3870 X2 requires 165 Watts. We would recommend a PSU with at least 350 Watts for the GeForce GT 640 and a PSU with at least 550 Watts for the HD 3870. The HD 3870 requires 100 Watts more than the GeForce GT 640 to run. The difference is significant enough that the HD 3870 may have an adverse affect on your yearly electricity bills in comparison to the GeForce GT 640.

Game FPS Benchmarks On Ultra

GPU Architecture

Core Speed902 MHzvs825 MHz
Boost Clock-vs-
ArchitectureKepler GK107-300-A2R600 RV670 XT
OC Potential Fair vs Poor
Driver Support Good vs Discontinued
Release Date05 Jun 2012vs28 Jan 2008
GPU LinkGD LinkGD Link

Resolution Performance

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GPU Memory

Memory2048 MBvs1024 MB
Memory Speed891 MHzvs900 MHz
Memory Bus128 Bitvs256 Bit
Memory TypeDDR3vsGDDR4
Memory Bandwidth28.5GB/secvs57.6GB/sec
L2 Cache 256 KB green tick vs 0 KB
Delta Color Compression no vs no
Memory Performance 0% green tick vs green tick 0%

GPU Display

Shader Processing Units384vs640
Actual Shader Performance17%vs25%
Texture Mapping Units32vs16
Texture Rate28.9 GTexel/svs13.2 GTexel/s
Render Output Units16vs16
Pixel Rate14.4 GPixel/svs13.2 GPixel/s

GPU Outputs

Max Digital Resolution (WxH)4096x2160vs2560x1600
VGA Connections1vs0
DVI Connections1vs2
HDMI Connections1vs0
DisplayPort Connections-vs-

GPU Power Requirements

Max Power65 Wattsvs165 Watts
Recommended PSU350 Watts & 26 Ampsvs550 Watts & 30 Amps

GPU Features

Shader Model5.0vs4.1
Open GL4.5vs3.3
Open CL-vs-
Notebook GPUnono

GPU Supporting Hardware

Recommended ProcessorIntel Core i3-3220 3.3GHzvsIntel Core 2 Duo E6850 3.0GHz
Recommended RAM8 GBvs4 GB
Maximum Recommended Gaming Resolution1366x768vs1440x900

Gaming Performance Value

Performance Value

GPU Mini Review

Mini ReviewOverview
GeForce GT 640 is a Middle-Class Graphics Card based on the first revision of the Kepler Architecture.

The Kepler Architecture was NVIDIA's big step to power efficiency. Each Stream Multiprocessor (SMX) now hosts 192 Shader Processing Units - against the 48 of older Fermi Architecture, and has been redesigned being now clocked at the same speed of the Central Unit. This means they are more energy efficient and will consequently lead to cooler operating temperatures. However, it also means they are weaker. It can be said that one Fermi SMX is as fast as 2 Kepler SMXs.
Additionally, and not available in all GPUs, Kepler also introduced the Boost Clock Feature. The Boost Clock is an even higher Clock Speed activated when in gaming mode and becomes the effective speed of the GPU.

It equips a GPU Codenamed GK107-300-A2 which has 2 Stream Multiprocessor activated and thus offers 384 Shader Processing Units, 32 TMUs and 16 ROPs. The Central Unit is clocked at 902MHz.

The GPU accesses a 2GB frame buffer of DDR3, through a 128-bit memory interface. The size of the frame buffer is exaggerated and in no way benefits the GPU. The Memory Clock Operates at 891MHz.

DirectX 11.0 Support (11.0 Hardware Default) and support for Optimus, CUDA, OpenCL, DirectCompute, 3D Vision Surround, PhysX, Realtime Raytracing and other technologies

Power Consumption
With a rated board TDP of 65W, it requires at least a 350W PSU and it relies entirely on the PCI Slot for power, meaning no extra connectors are required.

Gaming benchmarks put its performance on average with Radeon HD 6670.

System Suggestions
We recommend a Modest Processor (Intel Core i3) and 8GB of RAM for a system with GeForce GT 640.
Radeon HD 3870 X2 (not Crossfire) is a dual-graphics solution of two Radeon HD 3870.
This combination is expected to offer almost the same performance as Radeon HD 3870 Crossfired while consuming up to 25% less power. However, and just like Crossfire, its performance also relies a lot on proper driver support.
Today's modern demanding games will have to be played using the medium preset but with fluent frame rates. However, DirectX 11 games aren't supported.
Recommended CPU
Possible GPU Upgrades
GPU Variants