GeForce GTX 280 vs Radeon HD 4850 X2 1GB

Intro

Compare all that to the Radeon HD 4850 X2 1GB, which features a GPU core clock speed of 625 MHz, and 1024 MB of GDDR3 memory set to run at 993 MHz through a 256-bit bus. It also features 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 280		236 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 14 Watts (6%)

Memory Bandwidth

In theory, the GeForce GTX 280 should be 11% quicker than the Radeon HD 4850 X2 1GB in general, because of its higher data rate. (explain)

GeForce GTX 280		141696 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 14592 (11%)

Texel Rate

The Radeon HD 4850 X2 1GB is just a bit (approximately 4%) more effective at AF than the GeForce GTX 280. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
GeForce GTX 280		48160 Mtexels/sec
	Difference: 1840 (4%)

Pixel Rate

The Radeon HD 4850 X2 1GB will be a bit (about 4%) better at FSAA than the GeForce GTX 280, and also should be capable of handling higher screen resolutions better. (explain)

Radeon HD 4850 X2 1GB		20000 Mpixels/sec
GeForce GTX 280		19264 Mpixels/sec
	Difference: 736 (4%)

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 maximum amount of data (in units of megabytes per second) that can be transported past the external memory interface within a second. It's calculated by multiplying the bus width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better 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 amount of texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total number of texture units by the core 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 that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.