Geforce GTX 690 vs Radeon HD 4850 X2 512MB

Intro

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

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 X2 512MB		250 Watts
Geforce GTX 690		300 Watts
	Difference: 50 Watts (20%)

Memory Bandwidth

Theoretically speaking, the Geforce GTX 690 is 203% quicker than the Radeon HD 4850 X2 512MB overall, due to its greater data rate. (explain)

Geforce GTX 690		384512 MB/sec
Radeon HD 4850 X2 512MB		127104 MB/sec
	Difference: 257408 (203%)

Texel Rate

The Geforce GTX 690 is a lot (approximately 368%) faster with regards to AF than the Radeon HD 4850 X2 512MB. (explain)

Geforce GTX 690		234240 Mtexels/sec
Radeon HD 4850 X2 512MB		50000 Mtexels/sec
	Difference: 184240 (368%)

Pixel Rate

The Geforce GTX 690 should be quite a bit (more or less 193%) better at AA than the Radeon HD 4850 X2 512MB, and also will be capable of handling higher resolutions better. (explain)

Geforce GTX 690		58560 Mpixels/sec
Radeon HD 4850 X2 512MB		20000 Mpixels/sec
	Difference: 38560 (193%)

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 max amount of information (counted in megabytes per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total texture units of the card 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 processed per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill 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 ability to reach the max fill rate.