GeForce GTX 295 vs Radeon HD 4790

Intro

Compare all that to the Radeon HD 4790, which makes use of a 55 nm design. ATi has set the core speed at 600 MHz. The GDDR5 memory works at a frequency of 800 MHz on this specific model. It features 640(128x5) SPUs along with 32 Texture Address Units and 16 Rasterization Operator Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically, the GeForce GTX 295 should be much faster than the Radeon HD 4790 in general. (explain)

GeForce GTX 295		223776 MB/sec
Radeon HD 4790		102400 MB/sec
	Difference: 121376 (119%)

Texel Rate

The GeForce GTX 295 will be quite a bit (more or less 380%) more effective at anisotropic filtering than the Radeon HD 4790. (explain)

GeForce GTX 295		92160 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 72960 (380%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce GTX 295 is a better choice, and very much so. (explain)

GeForce GTX 295		32256 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 22656 (236%)

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 max amount of information (in units of megabytes per second) that can be transported over the external memory interface within a second. It is worked out by multiplying the bus width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.