Radeon HD 4850 512MB vs Radeon HD 7770

Intro

Compare all that to the Radeon HD 7770, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 RAM is set to run at a frequency of 1125 MHz on this particular model. It features 640 SPUs as well as 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
Radeon HD 4850 512MB		110 Watts
	Difference: 30 Watts (38%)

Memory Bandwidth

The Radeon HD 7770 should theoretically be a bit faster than the Radeon HD 4850 512MB in general. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 8448 (13%)

Texel Rate

The Radeon HD 7770 is a lot (about 60%) faster with regards to anisotropic filtering than the Radeon HD 4850 512MB. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4850 512MB		25000 Mtexels/sec
	Difference: 15000 (60%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 7770 is a better choice, by a large margin. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 6000 (60%)

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 maximum amount of information (in units of megabytes per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's 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 texture map elements (texels) that are processed per second. This is calculated by multiplying the total amount of texture units of the card by the core 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 per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.