Radeon HD 3850 512MB vs Radeon HD 4650 512MB

Intro

Compare those specifications to the Radeon HD 4650 512MB, which comes with GPU core speed of 600 MHz, and 512 MB of DDR2 memory running at 500 MHz through a 128-bit bus. It also is made up 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
Radeon HD 3850 512MB		75 Watts
	Difference: 20 Watts (36%)

Memory Bandwidth

As far as performance goes, the Radeon HD 3850 512MB should theoretically be quite a bit better than the Radeon HD 4650 512MB overall. (explain)

Radeon HD 3850 512MB		52992 MB/sec
Radeon HD 4650 512MB		16000 MB/sec
	Difference: 36992 (231%)

Texel Rate

The Radeon HD 4650 512MB is quite a bit (about 80%) better at AF than the Radeon HD 3850 512MB. (explain)

Radeon HD 4650 512MB		19200 Mtexels/sec
Radeon HD 3850 512MB		10688 Mtexels/sec
	Difference: 8512 (80%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 3850 512MB is superior to the Radeon HD 4650 512MB, by far. (explain)

Radeon HD 3850 512MB		10688 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 5888 (123%)

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 megabytes per second) that can be transported across the external memory interface within a second. It's calculated by multiplying the bus width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR 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 amount of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. 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 output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.