GeForce GTX 260 vs Radeon HD 4850 X2 512MB

Intro

Compare all of that to the Radeon HD 4850 X2 512MB, which comes with a core clock speed of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also makes use of a 256-bit bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 260		182 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 68 Watts (37%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4850 X2 512MB should be a little bit faster than the GeForce GTX 260 in general. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
GeForce GTX 260		111888 MB/sec
	Difference: 15216 (14%)

Texel Rate

The Radeon HD 4850 X2 512MB will be a lot (approximately 36%) more effective at anisotropic filtering than the GeForce GTX 260. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
GeForce GTX 260		36864 Mtexels/sec
	Difference: 13136 (36%)

Pixel Rate

The Radeon HD 4850 X2 512MB will be much (approximately 24%) faster with regards to AA than the GeForce GTX 260, and also will be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
GeForce GTX 260		16128 Mpixels/sec
	Difference: 3872 (24%)

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: Memory bandwidth is the maximum amount of data (counted in megabytes per second) that can be transported past the external memory interface within a second. It's worked out by multiplying the bus width by its memory clock speed. If the card has DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster 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 number is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.