GeForce 9400 GT 256MB vs Radeon HD 4650 512MB

Intro

Compare that to the Radeon HD 4650 512MB, which features clock speeds of 600 MHz on the GPU, and 500 MHz on the 512 MB of DDR2 RAM. It features 320(64x5) SPUs as well as 32 TAUs and 8 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 9400 GT 256MB		50 Watts
Radeon HD 4650 512MB		55 Watts
	Difference: 5 Watts (10%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4650 512MB should in theory be a lot better than the GeForce 9400 GT 256MB overall. (explain)

Radeon HD 4650 512MB		16000 MB/sec
GeForce 9400 GT 256MB		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The Radeon HD 4650 512MB should be a lot (about 336%) better at AF than the GeForce 9400 GT 256MB. (explain)

Radeon HD 4650 512MB		19200 Mtexels/sec
GeForce 9400 GT 256MB		4400 Mtexels/sec
	Difference: 14800 (336%)

Pixel Rate

The Radeon HD 4650 512MB will be a lot (approximately 118%) better at AA than the GeForce 9400 GT 256MB, and also should be capable of handling higher resolutions more effectively. (explain)

Radeon HD 4650 512MB		4800 Mpixels/sec
GeForce 9400 GT 256MB		2200 Mpixels/sec
	Difference: 2600 (118%)

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 max amount of information (in units of megabytes per second) that can be moved past the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.