GeForce GTX 660 vs Radeon HD 4870 X2

Intro

Compare that to the Radeon HD 4870 X2, which uses a 55 nm design. AMD has set the core speed at 750 MHz. The GDDR5 RAM is set to run at a frequency of 900 MHz on this particular 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 660		140 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 210 Watts (150%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 X2 is 60% faster than the GeForce GTX 660 overall, due to its greater bandwidth. (explain)

Radeon HD 4870 X2		230400 MB/sec
GeForce GTX 660		144192 MB/sec
	Difference: 86208 (60%)

Texel Rate

The GeForce GTX 660 should be quite a bit (approximately 31%) better at AF than the Radeon HD 4870 X2. (explain)

GeForce GTX 660		78400 Mtexels/sec
Radeon HD 4870 X2		60000 Mtexels/sec
	Difference: 18400 (31%)

Pixel Rate

The Radeon HD 4870 X2 is a little bit (more or less 2%) better at AA than the GeForce GTX 660, and also should be able to handle higher resolutions while still performing well. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
GeForce GTX 660		23520 Mpixels/sec
	Difference: 480 (2%)

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 largest amount of data (in units of megabytes per second) that can be moved across the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units 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 also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.