Radeon HD 4770 vs Radeon HD 6770

Intro

Compare all of that to the Radeon HD 6770, which has a clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also makes use of a 128-bit memory bus, and uses a 40 nm design. It is comprised of 800 SPUs, 40 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
Radeon HD 6770		108 Watts
	Difference: 28 Watts (35%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6770 should theoretically be much better than the Radeon HD 4770 in general. (explain)

Radeon HD 6770		67200 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 16000 (31%)

Texel Rate

The Radeon HD 6770 should be quite a bit (approximately 50%) better at anisotropic filtering than the Radeon HD 4770. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 12000 (50%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6770 is a better choice, though not by far. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4770		12000 Mpixels/sec
	Difference: 2400 (20%)

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 largest amount of data (in units of megabytes per second) that can be moved past the external memory interface in a second. It is worked out by multiplying the bus width by the speed of its memory. If it uses DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR 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 of the card by the core speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs 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 output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.