Radeon HD 4870 512MB vs Radeon HD 7750

Intro

Compare that to the Radeon HD 7750, which has core speeds of 800 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 512 SPUs along with 32 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7750		55 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 95 Watts (173%)

Memory Bandwidth

Theoretically, the Radeon HD 4870 512MB should perform much faster than the Radeon HD 7750 in general. (explain)

Radeon HD 4870 512MB		115200 MB/sec
Radeon HD 7750		72000 MB/sec
	Difference: 43200 (60%)

Texel Rate

The Radeon HD 4870 512MB should be a little bit (approximately 17%) better at anisotropic filtering than the Radeon HD 7750. (explain)

Radeon HD 4870 512MB		30000 Mtexels/sec
Radeon HD 7750		25600 Mtexels/sec
	Difference: 4400 (17%)

Pixel Rate

The Radeon HD 7750 should be a small bit (approximately 7%) better at full screen anti-aliasing than the Radeon HD 4870 512MB, and will be able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 7750		12800 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 800 (7%)

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 megabytes per second) that can be transferred over the external memory interface in a second. The number is worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the graphics 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 most pixels the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.