Radeon HD 4750 vs Radeon HD 4850 512MB

Intro

Compare those specs to the Radeon HD 4850 512MB, which features clock speeds of 625 MHz on the GPU, and 993 MHz on the 512 MB of GDDR3 RAM. It features 800(160x5) SPUs as well as 40 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 4750		75 Watts
Radeon HD 4850 512MB		110 Watts
	Difference: 35 Watts (47%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4850 512MB should be much faster than the Radeon HD 4750 overall. (explain)

Radeon HD 4850 512MB		63552 MB/sec
Radeon HD 4750		51200 MB/sec
	Difference: 12352 (24%)

Texel Rate

The Radeon HD 4850 512MB will be a little bit (more or less 7%) faster with regards to anisotropic filtering than the Radeon HD 4750. (explain)

Radeon HD 4850 512MB		25000 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 1640 (7%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 4750 is the winner, though not by far. (explain)

Radeon HD 4750		11680 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 1680 (17%)

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 data (in units of megabytes per second) that can be moved over the external memory interface in one second. It's worked out by multiplying the bus width by the speed of its memory. If it uses DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher 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 amount of texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling 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 chip can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour 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 rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.