GeForce 9800 GTX+ vs Radeon HD 4850 X2 512MB

Intro

Compare all that to the Radeon HD 4850 X2 512MB, which makes use of a 55 nm design. ATi has clocked the core frequency at 625 MHz. The GDDR3 RAM runs at a frequency of 993 MHz on this specific model. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 9800 GTX+		145 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 105 Watts (72%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4850 X2 512MB should theoretically be quite a bit superior to the GeForce 9800 GTX+ overall. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
GeForce 9800 GTX+		70400 MB/sec
	Difference: 56704 (81%)

Texel Rate

The Radeon HD 4850 X2 512MB is just a bit (more or less 6%) more effective at anisotropic filtering than the GeForce 9800 GTX+. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
GeForce 9800 GTX+		47232 Mtexels/sec
	Difference: 2768 (6%)

Pixel Rate

The Radeon HD 4850 X2 512MB will be much (more or less 69%) more effective at AA than the GeForce 9800 GTX+, and also able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
GeForce 9800 GTX+		11808 Mpixels/sec
	Difference: 8192 (69%)

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 information (measured in megabytes per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 are applied per second. This is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics 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 card could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.