GeForce GT 640 DDR3 vs Radeon HD 5450

Intro

Compare those specs to the Radeon HD 5450, which comes with core speeds of 650 MHz on the GPU, and 800 MHz on the 512 MB of DDR3 memory. It features 80(16x5) SPUs along with 8 Texture Address Units and 4 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5450		19 Watts
GeForce GT 640 DDR3		65 Watts
	Difference: 46 Watts (242%)

Memory Bandwidth

The GeForce GT 640 DDR3 should theoretically perform much faster than the Radeon HD 5450 overall. (explain)

GeForce GT 640 DDR3		57024 MB/sec
Radeon HD 5450		12800 MB/sec
	Difference: 44224 (346%)

Texel Rate

The GeForce GT 640 DDR3 should be quite a bit (about 454%) better at texture filtering than the Radeon HD 5450. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon HD 5450		5200 Mtexels/sec
	Difference: 23600 (454%)

Pixel Rate

The GeForce GT 640 DDR3 is a lot (approximately 454%) more effective at full screen anti-aliasing than the Radeon HD 5450, and also will be able to handle higher screen resolutions more effectively. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon HD 5450		2600 Mpixels/sec
	Difference: 11800 (454%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of data (counted in MB per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the interface width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.