GeForce GTX 275 vs Radeon HD 4870 512MB

Intro

Compare all that to the Radeon HD 4870 512MB, which uses a 55 nm design. AMD has clocked the core speed at 750 MHz. The GDDR5 RAM is set to run at a frequency of 900 MHz on this specific card. It features 800(160x5) SPUs as well as 40 Texture Address Units 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 will be 10% quicker than the Radeon HD 4870 512MB in general, because of its greater data rate. (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 (about 69%) more effective at anisotropic filtering 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

If using lots of anti-aliasing is important to you, then the GeForce GTX 275 is the winner, by a large margin. (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 (counted in MB per second) that can be transferred past the external memory interface in one second. The number is calculated by multiplying the bus width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. 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 can be applied in one second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling 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 can possibly record to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.