GeForce GTX 275 vs Radeon HD 4870 512MB

Intro

Compare those specifications to the Radeon HD 4870 512MB, which features core speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 512MB		150 Watts
GeForce GTX 275		219 Watts
	Difference: 69 Watts (46%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 275 should be 10% faster than the Radeon HD 4870 512MB overall, because of its greater bandwidth. (explain)

GeForce GTX 275		127008 MB/sec
Radeon HD 4870 512MB		115200 MB/sec
	Difference: 11808 (10%)

Texel Rate

The GeForce GTX 275 is much (approximately 69%) more effective at AF than the Radeon HD 4870 512MB. (explain)

GeForce GTX 275		50640 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 20640 (69%)

Pixel Rate

The GeForce GTX 275 is a lot (more or less 48%) more effective at anti-aliasing than the Radeon HD 4870 512MB, and capable of handling higher resolutions more effectively. (explain)

GeForce GTX 275		17724 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 5724 (48%)

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 largest amount of information (in units of megabytes per second) that can be moved across the external memory interface within a second. It is calculated by multiplying the bus width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.