Radeon HD 4850 2GB vs Radeon HD 7770

Intro

Compare all that to the Radeon HD 7770, which features 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 2GB		110 Watts
	Difference: 30 Watts (38%)

Memory Bandwidth

The Radeon HD 7770 should in theory be a 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 should be much (more or less 60%) more effective 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 should be quite a bit (more or less 60%) more effective at anti-aliasing than the Radeon HD 4850 2GB, and also able to handle higher resolutions without losing too much performance. (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 max amount of information (counted in megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the bus width by the speed of its memory. In the case of DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, 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 can be processed per second. This figure is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the graphics 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 most pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.