Radeon HD 4730 vs Radeon HD 7770

Intro

Compare all that to the Radeon HD 7770, which has a clock speed of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also features a 128-bit bus, and uses a 28 nm design. It is made up of 640 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
Radeon HD 4730		140 Watts
	Difference: 60 Watts (75%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7770 should be 25% faster than the Radeon HD 4730 overall, because of its greater data rate. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4730		57600 MB/sec
	Difference: 14400 (25%)

Texel Rate

The Radeon HD 7770 is much (more or less 79%) faster with regards to texture filtering than the Radeon HD 4730. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4730		22400 Mtexels/sec
	Difference: 17600 (79%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 7770 is the winner, and very much so. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4730		5600 Mpixels/sec
	Difference: 10400 (186%)

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 moved across the external memory interface within a second. It's calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR memory, the result should 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 can be processed in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the video 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 can possibly record to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.