Radeon HD 4850 1GB vs Radeon HD 7870

Intro

Compare all of that to the Radeon HD 7870, which makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory is set to run at a speed of 1200 MHz on this model. It features 1280 SPUs along with 80 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 1GB		110 Watts
Radeon HD 7870		175 Watts
	Difference: 65 Watts (59%)

Memory Bandwidth

The Radeon HD 7870, in theory, should perform quite a bit faster than the Radeon HD 4850 1GB in general. (explain)

Radeon HD 7870		153600 MB/sec
Radeon HD 4850 1GB		63552 MB/sec
	Difference: 90048 (142%)

Texel Rate

The Radeon HD 7870 should be a lot (approximately 220%) better at anisotropic filtering than the Radeon HD 4850 1GB. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon HD 4850 1GB		25000 Mtexels/sec
	Difference: 55000 (220%)

Pixel Rate

The Radeon HD 7870 is much (more or less 220%) faster with regards to full screen anti-aliasing than the Radeon HD 4850 1GB, and also should be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon HD 4850 1GB		10000 Mpixels/sec
	Difference: 22000 (220%)

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 information (in units of MB per second) that can be transported past the external memory interface within a second. It is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.