Radeon HD 4890 2GB vs Radeon HD 7750

Intro

Compare those specifications to the Radeon HD 7750, which features a core clock frequency of 800 MHz and a GDDR5 memory speed of 1125 MHz. It also makes use of a 128-bit bus, and uses a 28 nm design. It is made up of 512 SPUs, 32 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7750		55 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 135 Watts (245%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4890 2GB should be a lot faster than the Radeon HD 7750 in general. (explain)

Radeon HD 4890 2GB		124800 MB/sec
Radeon HD 7750		72000 MB/sec
	Difference: 52800 (73%)

Texel Rate

The Radeon HD 4890 2GB is much (about 56%) more effective at texture filtering than the Radeon HD 7750. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
Radeon HD 7750		25600 Mtexels/sec
	Difference: 14400 (56%)

Pixel Rate

The Radeon HD 4890 2GB will be quite a bit (about 25%) better at full screen anti-aliasing than the Radeon HD 7750, and also should be capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 4890 2GB		16000 Mpixels/sec
Radeon HD 7750		12800 Mpixels/sec
	Difference: 3200 (25%)

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 max amount of information (measured in MB per second) that can be transported past the external memory interface within a second. The number is calculated by multiplying the bus width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the core 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 - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.