Radeon HD 4870 1GB vs Radeon HD 5450

Intro

Compare that to the Radeon HD 5450, which features a core clock speed of 650 MHz and a DDR3 memory speed of 800 MHz. It also makes use of a 64-bit memory bus, and uses a 40 nm design. It is comprised of 80(16x5) SPUs, 8 Texture Address Units, and 4 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5450		19 Watts
Radeon HD 4870 1GB		150 Watts
	Difference: 131 Watts (689%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 1GB will be 800% quicker than the Radeon HD 5450 overall, because of its greater bandwidth. (explain)

Radeon HD 4870 1GB		115200 MB/sec
Radeon HD 5450		12800 MB/sec
	Difference: 102400 (800%)

Texel Rate

The Radeon HD 4870 1GB is a lot (approximately 477%) better at texture filtering than the Radeon HD 5450. (explain)

Radeon HD 4870 1GB		30000 Mtexels/sec
Radeon HD 5450		5200 Mtexels/sec
	Difference: 24800 (477%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 4870 1GB is the winner, by far. (explain)

Radeon HD 4870 1GB		12000 Mpixels/sec
Radeon HD 5450		2600 Mpixels/sec
	Difference: 9400 (362%)

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 maximum amount of information (measured in MB per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the graphics 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 maximum amount of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as 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 - the lower the bandwidth is, the lower the ability to reach the max fill rate.