Radeon HD 4750 vs Radeon HD 6750 1GB

Intro

Compare those specifications to the Radeon HD 6750 1GB, which makes use of a 40 nm design. AMD has set the core frequency at 725 MHz. The GDDR5 RAM runs at a frequency of 1000 MHz on this particular card. It features 720 SPUs along with 36 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 6750 1GB		86 Watts
	Difference: 11 Watts (15%)

Memory Bandwidth

The Radeon HD 6750 1GB should in theory be quite a bit faster than the Radeon HD 4750 overall. (explain)

Radeon HD 6750 1GB		64000 MB/sec
Radeon HD 4750		51200 MB/sec
	Difference: 12800 (25%)

Texel Rate

The Radeon HD 6750 1GB should be a bit (approximately 12%) faster with regards to anisotropic filtering than the Radeon HD 4750. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 2740 (12%)

Pixel Rate

The Radeon HD 4750 should be a small bit (more or less 1%) better at FSAA than the Radeon HD 6750 1GB, and will be capable of handling higher resolutions while still performing well. (explain)

Radeon HD 4750		11680 Mpixels/sec
Radeon HD 6750 1GB		11600 Mpixels/sec
	Difference: 80 (1%)

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 largest amount of data (in units of MB per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the interface width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could 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 clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.