Radeon HD 4650 512MB vs Radeon HD 6670 (OEM)

Intro

Compare those specs to the Radeon HD 6670 (OEM), which makes use of a 40 nm design. AMD has set the core speed at 800 MHz. The GDDR5 memory is set to run at a frequency of 1000 MHz on this specific card. It features 480 SPUs as well as 24 Texture Address Units and 8 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 512MB		55 Watts
Radeon HD 6670 (OEM)		63 Watts
	Difference: 8 Watts (15%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6670 (OEM) should be much faster than the Radeon HD 4650 512MB in general. (explain)

Radeon HD 6670 (OEM)		64000 MB/sec
Radeon HD 4650 512MB		16000 MB/sec
	Difference: 48000 (300%)

Texel Rate

Both cards have exactly the same texel rate, so in theory they should perform equally good at at anisotropic filtering. (explain)

Pixel Rate

The Radeon HD 6670 (OEM) is a lot (approximately 33%) more effective at anti-aliasing than the Radeon HD 4650 512MB, and will be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 6670 (OEM)		6400 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 1600 (33%)

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 (measured in megabytes per second) that can be transported across the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, 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 in one second. This is worked out by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.