GeForce 9800 GX2 vs Radeon HD 6770 1GB

Intro

Compare that to the Radeon HD 6770 1GB, which makes use of a 40 nm design. ATi has clocked the core frequency at 900 MHz. The GDDR5 RAM is set to run at a frequency of 1050 MHz on this model. It features 800 SPUs along with 40 TAUs and 16 Rasterization Operator Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770 1GB		108 Watts
GeForce 9800 GX2		197 Watts
	Difference: 89 Watts (82%)

Memory Bandwidth

As far as performance goes, the GeForce 9800 GX2 should in theory be much better than the Radeon HD 6770 1GB overall. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 6770 1GB		67200 MB/sec
	Difference: 60800 (90%)

Texel Rate

The GeForce 9800 GX2 will be quite a bit (approximately 113%) faster with regards to AF than the Radeon HD 6770 1GB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 6770 1GB		36000 Mtexels/sec
	Difference: 40800 (113%)

Pixel Rate

The GeForce 9800 GX2 will be quite a bit (more or less 33%) faster with regards to anti-aliasing than the Radeon HD 6770 1GB, and also will be able to handle higher resolutions without slowing down too much. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 6770 1GB		14400 Mpixels/sec
	Difference: 4800 (33%)

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 data (counted in MB per second) that can be transferred across the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video 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 the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.