Radeon HD 4750 vs Radeon HD 7790

Intro

Compare that to the Radeon HD 7790, which comes with core speeds of 1000 MHz on the GPU, and 1500 MHz on the 1024 MB of GDDR5 memory. It features 896 SPUs along with 56 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4750		75 Watts
Radeon HD 7790		85 Watts
	Difference: 10 Watts (13%)

Memory Bandwidth

Performance-wise, the Radeon HD 7790 should theoretically be quite a bit better than the Radeon HD 4750 in general. (explain)

Radeon HD 7790		96000 MB/sec
Radeon HD 4750		51200 MB/sec
	Difference: 44800 (88%)

Texel Rate

The Radeon HD 7790 will be quite a bit (more or less 140%) better at anisotropic filtering than the Radeon HD 4750. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 32640 (140%)

Pixel Rate

The Radeon HD 7790 is a lot (about 37%) better at full screen anti-aliasing than the Radeon HD 4750, and also able to handle higher resolutions more effectively. (explain)

Radeon HD 7790		16000 Mpixels/sec
Radeon HD 4750		11680 Mpixels/sec
	Difference: 4320 (37%)

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: Bandwidth is the max amount of information (counted in MB per second) that can be transported over the external memory interface within a second. The number is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher 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 amount of texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, the better the 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 most pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.