GeForce GT 640 DDR3 vs Radeon HD 4550 512MB

Intro

Compare those specs to the Radeon HD 4550 512MB, which has a core clock speed of 600 MHz and a GDDR3 memory frequency of 800 MHz. It also uses a 64-bit bus, and makes use of a 55 nm design. It is made up of 80(16x5) SPUs, 8 TAUs, and 4 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4550 512MB		25 Watts
GeForce GT 640 DDR3		65 Watts
	Difference: 40 Watts (160%)

Memory Bandwidth

In theory, the GeForce GT 640 DDR3 should perform much faster than the Radeon HD 4550 512MB in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
Radeon HD 4550 512MB		12800 MB/sec
	Difference: 44224 (346%)

Texel Rate

The GeForce GT 640 DDR3 should be a lot (approximately 500%) more effective at AF than the Radeon HD 4550 512MB. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon HD 4550 512MB		4800 Mtexels/sec
	Difference: 24000 (500%)

Pixel Rate

The GeForce GT 640 DDR3 is a lot (approximately 500%) better at anti-aliasing than the Radeon HD 4550 512MB, and able to handle higher resolutions without losing too much performance. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon HD 4550 512MB		2400 Mpixels/sec
	Difference: 12000 (500%)

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 largest amount of data (measured in MB per second) that can be transferred over the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write 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 card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called 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, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.