Geforce GTX 680 vs Radeon HD 4650 512MB

Intro

Compare all of that to the Radeon HD 4650 512MB, which comes with GPU core speed of 600 MHz, and 512 MB of DDR2 RAM running at 500 MHz through a 128-bit bus. It also is comprised of 320(64x5) SPUs, 32 Texture Address Units, and 8 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 512MB		55 Watts
Geforce GTX 680		195 Watts
	Difference: 140 Watts (255%)

Memory Bandwidth

Theoretically speaking, the Geforce GTX 680 should be much faster than the Radeon HD 4650 512MB in general. (explain)

Geforce GTX 680		192256 MB/sec
Radeon HD 4650 512MB		16000 MB/sec
	Difference: 176256 (1102%)

Texel Rate

The Geforce GTX 680 is quite a bit (approximately 571%) more effective at AF than the Radeon HD 4650 512MB. (explain)

Geforce GTX 680		128768 Mtexels/sec
Radeon HD 4650 512MB		19200 Mtexels/sec
	Difference: 109568 (571%)

Pixel Rate

The Geforce GTX 680 is quite a bit (more or less 571%) faster with regards to anti-aliasing than the Radeon HD 4650 512MB, and able to handle higher screen resolutions without slowing down too much. (explain)

Geforce GTX 680		32192 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 27392 (571%)

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 max amount of data (in units of megabytes per second) that can be transported past the external memory interface in one second. It is calculated by multiplying the bus width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster 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 in one second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the 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 most pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output 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 potential to reach the maximum fill rate.