Radeon HD 4850 1GB vs Radeon HD 7770

Intro

Compare all of that to the Radeon HD 7770, which has core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
Radeon HD 4850 1GB		110 Watts
	Difference: 30 Watts (38%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7770 should be a small bit faster than the Radeon HD 4850 1GB in general. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4850 1GB		63552 MB/sec
	Difference: 8448 (13%)

Texel Rate

The Radeon HD 7770 will be much (about 60%) better at AF than the Radeon HD 4850 1GB. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4850 1GB		25000 Mtexels/sec
	Difference: 15000 (60%)

Pixel Rate

The Radeon HD 7770 should be quite a bit (more or less 60%) more effective at FSAA than the Radeon HD 4850 1GB, and also should be capable of handling higher resolutions better. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4850 1GB		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: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the bus width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is worked out by multiplying the total number of texture units of the card 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 the video card could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.