Radeon HD 4850 2GB vs Radeon HD 7770

Intro

Compare all of that to the Radeon HD 7770, which features GPU core speed of 1000 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is comprised of 640 Stream Processors, 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 4850 2GB		110 Watts
	Difference: 30 Watts (38%)

Memory Bandwidth

The Radeon HD 7770, in theory, should be a little bit faster than the Radeon HD 4850 2GB in general. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4850 2GB		63552 MB/sec
	Difference: 8448 (13%)

Texel Rate

The Radeon HD 7770 will be quite a bit (about 60%) better at texture filtering than the Radeon HD 4850 2GB. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4850 2GB		25000 Mtexels/sec
	Difference: 15000 (60%)

Pixel Rate

The Radeon HD 7770 is much (about 60%) more effective at full screen anti-aliasing than the Radeon HD 4850 2GB, and also capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4850 2GB		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 data (counted in megabytes per second) that can be transported past the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type RAM, the result 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 AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the 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 number of pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of 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 many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.