GeForce GT 640 DDR3 vs Radeon HD 4730

Intro

Compare all of that to the Radeon HD 4730, which makes use of a 55 nm design. AMD has set the core speed at 700 MHz. The GDDR5 RAM is set to run at a speed of 900 MHz on this particular card. It features 640(128x5) SPUs as well as 32 Texture Address Units and 8 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 4730		140 Watts
	Difference: 75 Watts (115%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4730 should theoretically be just a bit superior to the GeForce GT 640 DDR3 overall. (explain)

Radeon HD 4730		57600 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 576 (1%)

Texel Rate

The GeForce GT 640 DDR3 will be quite a bit (about 29%) more effective at texture filtering than the Radeon HD 4730. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon HD 4730		22400 Mtexels/sec
	Difference: 6400 (29%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce GT 640 DDR3 is a better choice, by far. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon HD 4730		5600 Mpixels/sec
	Difference: 8800 (157%)

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 information (measured in MB per second) that can be moved over the external memory interface in a second. It is calculated by multiplying the interface width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This is worked out by multiplying the total number of 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 in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.