Radeon HD 5770 vs Radeon HD 7870 XT

Intro

Compare all of that to the Radeon HD 7870 XT, which features a core clock frequency of 925 MHz and a GDDR5 memory speed of 1500 MHz. It also uses a 256-bit bus, and uses a 28 nm design. It is comprised 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 much (approximately 161%) more effective at AF than the Radeon HD 5770. (explain)

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

Pixel Rate

The Radeon HD 7870 XT is much (more or less 118%) faster with regards to full screen anti-aliasing than the Radeon HD 5770, and will be able to handle higher resolutions without losing too much performance. (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 largest amount of information (in units of MB per second) that can be transferred past the external memory interface in a second. It's worked out by multiplying the bus width by the speed of its memory. In the case of DDR RAM, the result 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 AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units 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 rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.