Radeon HD 4670 512MB vs Radeon HD 4770

Intro

Compare those specs to the Radeon HD 4770, which comes with a clock frequency of 750 MHz and a GDDR5 memory frequency of 800 MHz. It also uses a 128-bit memory bus, and makes use of a 40 nm design. It is comprised of 640(128x5) SPUs, 32 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4670 512MB		70 Watts
Radeon HD 4770		80 Watts
	Difference: 10 Watts (14%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4770 should be 60% quicker than the Radeon HD 4670 512MB in general, due to its greater data rate. (explain)

Radeon HD 4770		51200 MB/sec
Radeon HD 4670 512MB		32000 MB/sec
	Difference: 19200 (60%)

Texel Rate

Both cards have exactly the same texel fill rate, so theoretically they should be equally good at at anisotropic filtering. (explain)

Pixel Rate

The Radeon HD 4770 should be quite a bit (more or less 100%) more effective at anti-aliasing than the Radeon HD 4670 512MB, and will be able to handle higher screen resolutions better. (explain)

Radeon HD 4770		12000 Mpixels/sec
Radeon HD 4670 512MB		6000 Mpixels/sec
	Difference: 6000 (100%)

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 max amount of data (measured in megabytes per second) that can be moved 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, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the most pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill 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 ability to reach the max fill rate.