Radeon HD 4770 vs Radeon HD 5870

Intro

Compare that to the Radeon HD 5870, which makes use of a 40 nm design. AMD has set the core frequency at 850 MHz. The GDDR5 RAM runs at a speed of 1200 MHz on this particular model. It features 1600(320x5) SPUs as well as 80 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
Radeon HD 5870		188 Watts
	Difference: 108 Watts (135%)

Memory Bandwidth

Performance-wise, the Radeon HD 5870 should theoretically be quite a bit superior to the Radeon HD 4770 overall. (explain)

Radeon HD 5870		153600 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 102400 (200%)

Texel Rate

The Radeon HD 5870 should be quite a bit (about 183%) faster with regards to AF than the Radeon HD 4770. (explain)

Radeon HD 5870		68000 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 44000 (183%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 5870 is the winner, and very much so. (explain)

Radeon HD 5870		27200 Mpixels/sec
Radeon HD 4770		12000 Mpixels/sec
	Difference: 15200 (127%)

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 (in units of MB per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the interface width by the speed of its memory. In the case of DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is calculated by multiplying the total amount of texture units by the core 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 a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.