Radeon HD 4870 2GB vs Radeon HD 7850

Intro

Compare all that to the Radeon HD 7850, which comes with core speeds of 860 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1024 SPUs along with 64 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7850		130 Watts
Radeon HD 4870 2GB		150 Watts
	Difference: 20 Watts (15%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7850 should perform a lot faster than the Radeon HD 4870 2GB overall. (explain)

Radeon HD 7850		153600 MB/sec
Radeon HD 4870 2GB		115200 MB/sec
	Difference: 38400 (33%)

Texel Rate

The Radeon HD 7850 will be a lot (more or less 83%) more effective at AF than the Radeon HD 4870 2GB. (explain)

Radeon HD 7850		55040 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 25040 (83%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 7850 is superior to the Radeon HD 4870 2GB, by a large margin. (explain)

Radeon HD 7850		27520 Mpixels/sec
Radeon HD 4870 2GB		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: Memory bandwidth is the largest amount of data (measured in megabytes per second) that can be transported past the external memory interface within a second. It's worked out by multiplying the interface width by its memory clock speed. If it uses DDR type memory, it must 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 AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.