Radeon HD 4750 vs Radeon HD 7750

Intro

Compare those specs to the Radeon HD 7750, which uses a 28 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 RAM works at a speed of 1125 MHz on this specific card. It features 512 SPUs along with 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 4750		75 Watts
	Difference: 20 Watts (36%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7750 should in theory be much superior to the Radeon HD 4750 overall. (explain)

Radeon HD 7750		72000 MB/sec
Radeon HD 4750		51200 MB/sec
	Difference: 20800 (41%)

Texel Rate

The Radeon HD 7750 will be a small bit (approximately 10%) better at anisotropic filtering than the Radeon HD 4750. (explain)

Radeon HD 7750		25600 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 2240 (10%)

Pixel Rate

The Radeon HD 7750 is a small bit (approximately 10%) better at anti-aliasing than the Radeon HD 4750, and also will be able to handle higher screen resolutions better. (explain)

Radeon HD 7750		12800 Mpixels/sec
Radeon HD 4750		11680 Mpixels/sec
	Difference: 1120 (10%)

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 maximum amount of data (measured in megabytes per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, 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 figure is worked out by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.