GeForce GT 640 DDR3 vs Radeon HD 3650 256MB

Intro

Compare that to the Radeon HD 3650 256MB, which uses a 55 nm design. AMD has clocked the core speed at 725 MHz. The DDR2 RAM runs at a frequency of 800 MHz on this specific model. It features 120(24x5) SPUs as well as 8 TAUs and 4 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 3650 256MB		78 Watts
	Difference: 13 Watts (20%)

Memory Bandwidth

In theory, the GeForce GT 640 DDR3 will be 123% faster than the Radeon HD 3650 256MB overall, because of its higher data rate. (explain)

GeForce GT 640 DDR3		57024 MB/sec
Radeon HD 3650 256MB		25600 MB/sec
	Difference: 31424 (123%)

Texel Rate

The GeForce GT 640 DDR3 is quite a bit (about 397%) more effective at texture filtering than the Radeon HD 3650 256MB. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon HD 3650 256MB		5800 Mtexels/sec
	Difference: 23000 (397%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the GeForce GT 640 DDR3 is the winner, and very much so. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon HD 3650 256MB		2900 Mpixels/sec
	Difference: 11500 (397%)

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: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be transported over the external memory interface within a second. The number is calculated by multiplying the card's interface width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, 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 amount of pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.