Radeon HD 7870 XT vs Radeon HD 7950 3GB

Intro

Compare all that to the Radeon HD 7950 3GB, which makes use of a 28 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 RAM is set to run at a speed of 1250 MHz on this model. It features 1792 SPUs along with 112 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7870 XT		185 Watts
Radeon HD 7950 3GB		200 Watts
	Difference: 15 Watts (8%)

Memory Bandwidth

Performance-wise, the Radeon HD 7950 3GB should theoretically be a lot superior to the Radeon HD 7870 XT overall. (explain)

Radeon HD 7950 3GB		240000 MB/sec
Radeon HD 7870 XT		192000 MB/sec
	Difference: 48000 (25%)

Texel Rate

The Radeon HD 7950 3GB is a small bit (about 1%) more effective at AF than the Radeon HD 7870 XT. (explain)

Radeon HD 7950 3GB		89600 Mtexels/sec
Radeon HD 7870 XT		88800 Mtexels/sec
	Difference: 800 (1%)

Pixel Rate

The Radeon HD 7870 XT is a small bit (approximately 16%) more effective at FSAA than the Radeon HD 7950 3GB, and will be able to handle higher screen resolutions better. (explain)

Radeon HD 7870 XT		29600 Mpixels/sec
Radeon HD 7950 3GB		25600 Mpixels/sec
	Difference: 4000 (16%)

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 maximum amount of information (counted in MB per second) that can be moved past the external memory interface within a second. It is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better 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 can be applied per second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number 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 fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.