GeForce 9800 GX2 vs Radeon HD 7770

Intro

Compare those specifications to the Radeon HD 7770, which features a clock speed of 1000 MHz and a GDDR5 memory frequency of 1125 MHz. It also features a 128-bit memory bus, and makes use of a 28 nm design. It features 640 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 7770		80 Watts
GeForce 9800 GX2		197 Watts
	Difference: 117 Watts (146%)

Memory Bandwidth

As far as performance goes, the GeForce 9800 GX2 should in theory be much superior to the Radeon HD 7770 overall. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 7770		72000 MB/sec
	Difference: 56000 (78%)

Texel Rate

The GeForce 9800 GX2 should be quite a bit (more or less 92%) more effective at anisotropic filtering than the Radeon HD 7770. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 7770		40000 Mtexels/sec
	Difference: 36800 (92%)

Pixel Rate

The GeForce 9800 GX2 should be a small bit (about 20%) faster with regards to FSAA than the Radeon HD 7770, and also capable of handling higher resolutions better. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 7770		16000 Mpixels/sec
	Difference: 3200 (20%)

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 bus width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units 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 output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.