Radeon HD 4790 vs Radeon HD 7790

Intro

Compare those specifications to the Radeon HD 7790, which comes with GPU clock speed of 1000 MHz, and 1024 MB of GDDR5 memory set to run at 1500 MHz through a 128-bit bus. It also is comprised of 896 SPUs, 56 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The Radeon HD 4790 should in theory be just a bit faster than the Radeon HD 7790 overall. (explain)

Radeon HD 4790		102400 MB/sec
Radeon HD 7790		96000 MB/sec
	Difference: 6400 (7%)

Texel Rate

The Radeon HD 7790 should be quite a bit (approximately 192%) better at anisotropic filtering than the Radeon HD 4790. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 36800 (192%)

Pixel Rate

The Radeon HD 7790 will be quite a bit (about 67%) better at FSAA than the Radeon HD 4790, and also capable of handling higher screen resolutions better. (explain)

Radeon HD 7790		16000 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 6400 (67%)

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 largest amount of information (counted in MB per second) that can be transported across the external memory interface within a second. The number is calculated by multiplying the interface width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, 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 texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.