Radeon HD 4670 1GB vs Radeon HD 7790

Intro

Compare all of that to the Radeon HD 7790, which uses a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory works at a speed of 1500 MHz on this model. It features 896 SPUs along with 56 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4670 1GB		70 Watts
Radeon HD 7790		85 Watts
	Difference: 15 Watts (21%)

Memory Bandwidth

In theory, the Radeon HD 7790 should be quite a bit faster than the Radeon HD 4670 1GB overall. (explain)

Radeon HD 7790		96000 MB/sec
Radeon HD 4670 1GB		35200 MB/sec
	Difference: 60800 (173%)

Texel Rate

The Radeon HD 7790 is much (about 133%) better at texture filtering than the Radeon HD 4670 1GB. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon HD 4670 1GB		24000 Mtexels/sec
	Difference: 32000 (133%)

Pixel Rate

The Radeon HD 7790 should be a lot (about 167%) faster with regards to full screen anti-aliasing than the Radeon HD 4670 1GB, and also capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 7790		16000 Mpixels/sec
Radeon HD 4670 1GB		6000 Mpixels/sec
	Difference: 10000 (167%)

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 maximum amount of data (measured in MB per second) that can be transported past the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster 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 can be processed in one second. This number is worked out by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at 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 that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of 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.