GeForce GTX 280 vs Radeon HD 4850 X2 1GB

Intro

Compare those specifications to the Radeon HD 4850 X2 1GB, which has a clock frequency of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also makes use of a 256-bit memory 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)

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

Memory Bandwidth

The GeForce GTX 280 should theoretically perform a bit faster than the Radeon HD 4850 X2 1GB overall. (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 a little bit (more or less 4%) better at texture filtering 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 is a small bit (more or less 4%) more effective at full screen anti-aliasing than the GeForce GTX 280, and also able to handle higher resolutions more effectively. (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 largest amount of information (counted in MB per second) that can be moved over the external memory interface in one second. The number is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better 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 can be processed per second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the most 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 the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.