GeForce GTX 260 216SP 55 nm vs Radeon HD 4790

Intro

Compare that to the Radeon HD 4790, which has GPU clock speed of 600 MHz, and 512 MB of GDDR5 memory running at 800 MHz through a 256-bit bus. It also features 640(128x5) SPUs, 32 Texture Address Units, and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the GeForce GTX 260 216SP 55 nm will be 9% quicker than the Radeon HD 4790 in general, because of its higher bandwidth. (explain)

GeForce GTX 260 216SP 55 nm		111888 MB/sec
Radeon HD 4790		102400 MB/sec
	Difference: 9488 (9%)

Texel Rate

The GeForce GTX 260 216SP 55 nm will be a lot (about 116%) better at AF than the Radeon HD 4790. (explain)

GeForce GTX 260 216SP 55 nm		41472 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 22272 (116%)

Pixel Rate

The GeForce GTX 260 216SP 55 nm will be quite a bit (approximately 68%) more effective at AA than the Radeon HD 4790, and also capable of handling higher screen resolutions while still performing well. (explain)

GeForce GTX 260 216SP 55 nm		16128 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 6528 (68%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (measured in megabytes per second) that can be moved across the external memory interface in a second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the 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 maximum number of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.