Radeon HD 4750 vs Radeon HD 4770

Intro

Compare those specs to the Radeon HD 4770, which makes use of a 40 nm design. AMD has set the core frequency at 750 MHz. The GDDR5 memory works at a speed of 800 MHz on this particular model. It features 640(128x5) 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 4750		75 Watts
Radeon HD 4770		80 Watts
	Difference: 5 Watts (7%)

Memory Bandwidth

Both cards have the exact same memory bandwidth, so theoretically they should have the same performance. (explain)

Texel Rate

The Radeon HD 4770 should be a small bit (more or less 3%) faster with regards to anisotropic filtering than the Radeon HD 4750. (explain)

Radeon HD 4770		24000 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 640 (3%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 4770 is a better choice, though not by far. (explain)

Radeon HD 4770		12000 Mpixels/sec
Radeon HD 4750		11680 Mpixels/sec
	Difference: 320 (3%)

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 information (measured in megabytes per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 again. If 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 amount of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total number of texture units of the card 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 in a second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.