GeForce GTX 470 vs Radeon HD 4850 X2 512MB

Intro

Compare that to the Radeon HD 4850 X2 512MB, which comes with a clock speed of 625 MHz and a GDDR3 memory speed of 993 MHz. It also features a 256-bit bus, and makes use of a 55 nm design. It is made up of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 470		215 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 35 Watts (16%)

Memory Bandwidth

The GeForce GTX 470 should in theory perform a little bit faster than the Radeon HD 4850 X2 512MB overall. (explain)

GeForce GTX 470		133920 MB/sec
Radeon HD 4850 X2 512MB		127104 MB/sec
	Difference: 6816 (5%)

Texel Rate

The Radeon HD 4850 X2 512MB is much (more or less 47%) better at texture filtering than the GeForce GTX 470. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
GeForce GTX 470		33992 Mtexels/sec
	Difference: 16008 (47%)

Pixel Rate

The GeForce GTX 470 should be a lot (about 21%) better at FSAA than the Radeon HD 4850 X2 512MB, and capable of handling higher resolutions without losing too much performance. (explain)

GeForce GTX 470		24280 Mpixels/sec
Radeon HD 4850 X2 512MB		20000 Mpixels/sec
	Difference: 4280 (21%)

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 MB per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, the result 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 AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock 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 applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.