Radeon HD 4870 512MB vs Radeon HD 7850

Intro

Compare that to the Radeon HD 7850, which comes with clock speeds of 860 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1024 SPUs along with 64 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7850		130 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 20 Watts (15%)

Memory Bandwidth

In theory, the Radeon HD 7850 should be much faster than the Radeon HD 4870 512MB in general. (explain)

Radeon HD 7850		153600 MB/sec
Radeon HD 4870 512MB		115200 MB/sec
	Difference: 38400 (33%)

Texel Rate

The Radeon HD 7850 will be much (approximately 83%) better at texture filtering than the Radeon HD 4870 512MB. (explain)

Radeon HD 7850		55040 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 25040 (83%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 7850 is superior to the Radeon HD 4870 512MB, by a large margin. (explain)

Radeon HD 7850		27520 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 15520 (129%)

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 data (in units of MB per second) that can be transferred past the external memory interface in a second. It is worked out by multiplying the bus width by its memory clock speed. In the case of DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total texture units of the card by the core 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 processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.