Radeon HD 4650 512MB vs Radeon HD 6450 (OEM)

Intro

Compare those specifications to the Radeon HD 6450 (OEM), which comes with clock speeds of 625 MHz on the GPU, and 800 MHz on the 512 MB of GDDR3 memory. It features 160 SPUs along with 8 TAUs and 4 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6450 (OEM)		31 Watts
Radeon HD 4650 512MB		55 Watts
	Difference: 24 Watts (77%)

Memory Bandwidth

In theory, the Radeon HD 4650 512MB will be 25% quicker than the Radeon HD 6450 (OEM) overall, because of its higher data rate. (explain)

Radeon HD 4650 512MB		16000 MB/sec
Radeon HD 6450 (OEM)		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The Radeon HD 4650 512MB is a lot (more or less 284%) more effective at texture filtering than the Radeon HD 6450 (OEM). (explain)

Radeon HD 4650 512MB		19200 Mtexels/sec
Radeon HD 6450 (OEM)		5000 Mtexels/sec
	Difference: 14200 (284%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 4650 512MB is a better choice, by a large margin. (explain)

Radeon HD 4650 512MB		4800 Mpixels/sec
Radeon HD 6450 (OEM)		2500 Mpixels/sec
	Difference: 2300 (92%)

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 over the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. If the card has DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number 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 speed of the chip. The better 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 most pixels that the graphics chip can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.