Radeon HD 4890 2GB vs Radeon HD 6450 (OEM) 1GB

Intro

Compare all of that to the Radeon HD 6450 (OEM) 1GB, which comes with clock speeds of 750 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR5 memory. It features 160 SPUs along with 8 Texture Address Units and 4 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6450 (OEM) 1GB		31 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 159 Watts (513%)

Memory Bandwidth

Theoretically, the Radeon HD 4890 2GB should be a lot faster than the Radeon HD 6450 (OEM) 1GB overall. (explain)

Radeon HD 4890 2GB		124800 MB/sec
Radeon HD 6450 (OEM) 1GB		28800 MB/sec
	Difference: 96000 (333%)

Texel Rate

The Radeon HD 4890 2GB is much (more or less 567%) more effective at AF than the Radeon HD 6450 (OEM) 1GB. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
Radeon HD 6450 (OEM) 1GB		6000 Mtexels/sec
	Difference: 34000 (567%)

Pixel Rate

The Radeon HD 4890 2GB should be a lot (about 433%) faster with regards to AA than the Radeon HD 6450 (OEM) 1GB, and will be able to handle higher screen resolutions better. (explain)

Radeon HD 4890 2GB		16000 Mpixels/sec
Radeon HD 6450 (OEM) 1GB		3000 Mpixels/sec
	Difference: 13000 (433%)

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 within a second. The number is calculated by multiplying the card's interface width by its memory speed. If it uses DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core 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 fill rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.