Radeon HD 4650 1GB vs Radeon HD 7790

Intro

Compare all that to the Radeon HD 7790, which uses a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory runs at a speed of 1500 MHz on this model. It features 896 SPUs as well as 56 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 1GB		55 Watts
Radeon HD 7790		85 Watts
	Difference: 30 Watts (55%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7790 should perform a lot faster than the Radeon HD 4650 1GB overall. (explain)

Radeon HD 7790		96000 MB/sec
Radeon HD 4650 1GB		22400 MB/sec
	Difference: 73600 (329%)

Texel Rate

The Radeon HD 7790 will be much (approximately 192%) more effective at anisotropic filtering than the Radeon HD 4650 1GB. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon HD 4650 1GB		19200 Mtexels/sec
	Difference: 36800 (192%)

Pixel Rate

The Radeon HD 7790 is much (approximately 233%) more effective at AA than the Radeon HD 4650 1GB, and able to handle higher resolutions better. (explain)

Radeon HD 7790		16000 Mpixels/sec
Radeon HD 4650 1GB		4800 Mpixels/sec
	Difference: 11200 (233%)

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 data (counted in MB per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the card's bus width by its memory clock speed. In the case of DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 processed in one second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics 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 amount of pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.