Radeon HD 4870 1GB vs Radeon HD 7750

Intro

Compare those specs to the Radeon HD 7750, which has core clock speeds of 800 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 512 SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7750		55 Watts
Radeon HD 4870 1GB		150 Watts
	Difference: 95 Watts (173%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 1GB should theoretically be quite a bit better than the Radeon HD 7750 in general. (explain)

Radeon HD 4870 1GB		115200 MB/sec
Radeon HD 7750		72000 MB/sec
	Difference: 43200 (60%)

Texel Rate

The Radeon HD 4870 1GB should be just a bit (more or less 17%) more effective at anisotropic filtering than the Radeon HD 7750. (explain)

Radeon HD 4870 1GB		30000 Mtexels/sec
Radeon HD 7750		25600 Mtexels/sec
	Difference: 4400 (17%)

Pixel Rate

The Radeon HD 7750 should be just a bit (approximately 7%) better at full screen anti-aliasing than the Radeon HD 4870 1GB, and also should be capable of handling higher resolutions more effectively. (explain)

Radeon HD 7750		12800 Mpixels/sec
Radeon HD 4870 1GB		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 max amount of information (counted in megabytes per second) that can be transported over the external memory interface within a second. It is calculated by multiplying the bus width by its memory speed. In the case of DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

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