GeForce GTX 275 vs Radeon HD 4870 X2

Intro

Compare those specs to the Radeon HD 4870 X2, which makes use of a 55 nm design. AMD has set the core frequency at 750 MHz. The GDDR5 memory is set to run at a speed of 900 MHz on this card. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 275		219 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 131 Watts (60%)

Memory Bandwidth

In theory, the Radeon HD 4870 X2 should perform quite a bit faster than the GeForce GTX 275 in general. (explain)

Radeon HD 4870 X2		230400 MB/sec
GeForce GTX 275		127008 MB/sec
	Difference: 103392 (81%)

Texel Rate

The Radeon HD 4870 X2 should be a bit (more or less 18%) better at texture filtering than the GeForce GTX 275. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
GeForce GTX 275		50640 Mtexels/sec
	Difference: 9360 (18%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 4870 X2 is a better choice, by a large margin. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
GeForce GTX 275		17724 Mpixels/sec
	Difference: 6276 (35%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (in units of MB per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better 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 number of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the graphics 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 most pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.