Radeon HD 5770 vs Radeon HD 7870 XT

Intro

Compare those specs to the Radeon HD 7870 XT, which comes with a core clock speed of 925 MHz and a GDDR5 memory frequency of 1500 MHz. It also features a 256-bit memory bus, and uses a 28 nm design. It is made up of 1536 SPUs, 96 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5770		108 Watts
Radeon HD 7870 XT		185 Watts
	Difference: 77 Watts (71%)

Memory Bandwidth

In theory, the Radeon HD 7870 XT should be much faster than the Radeon HD 5770 in general. (explain)

Radeon HD 7870 XT		192000 MB/sec
Radeon HD 5770		76800 MB/sec
	Difference: 115200 (150%)

Texel Rate

The Radeon HD 7870 XT is quite a bit (approximately 161%) faster with regards to texture filtering than the Radeon HD 5770. (explain)

Radeon HD 7870 XT		88800 Mtexels/sec
Radeon HD 5770		34000 Mtexels/sec
	Difference: 54800 (161%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 7870 XT is the winner, and very much so. (explain)

Radeon HD 7870 XT		29600 Mpixels/sec
Radeon HD 5770		13600 Mpixels/sec
	Difference: 16000 (118%)

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 MB per second) that can be transferred past the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.